D12 unit 6 algebra 1 assignment all methods of solving quadratics answers. 8 There are always 2 solutions to quadratics.
- D12 unit 6 algebra 1 assignment all methods of solving quadratics answers 6. The gamification activity is designed to support active learning. 5. 1_ca. First, scholars review how to simplify radicals and add and subtract radical expressions with different radicands. Hon Geom Quadratics Unit C 2 0 1 9 K ut a S o ft w are LL Solving Quadratic Equations Using All Methods Date_ Solve each equation by factoring. a. B. 4 1 0 obj /Title (þÿInfinite Algebra 2 - Solving Quadratic Equations Using All Methods) /Creator (þÿ) /Producer (þÿQt 5. The review assignment is posted below, as well as the answer key to the assignment. , 12-13, 15-19 o. , 5(3x – 1)2], using a a method of showing how data is distributed by using the median, quartiles, and minimum and maximum values solution of a system of equations a set of values that make all equations in a system true Solving Quadratics - All Methods Solve using the Quadratic Formula - Level 2 1) n2 + 9n + 11 = 0 2) 5p2 − 125 = 0 3) m2 + 5m + 6 = 0 4) 2x2 − 4x − 30 = 0 Solve using the Quadratic Formula - Level 3 5) b2 − 12 b + 10 = −10 6) 6r2 − 5r − 4 = 7 7) 7x2 − 16 = 6 8) 6n2 − 10 n − 16 = 3 Solve using the Quadratic Formula - Level 4 This Quadratic Equations & Complex Numbers Unit Bundle includes guided notes, homework assignments, three quizzes, a study guide and a unit test that cover the following topics:• Roots of a Quadratic Equation; Solving Quadratics by Graphing• Factoring Review• Solving Quadratics by Factoring• Fac %PDF-1. :๐ฅ10 ; 6 L121 3. Answers should be exact (simplified radical) unless otherwise indicated. , 19, 37-39 o. õ. The final unit in the Algebra 1 Common Core Flipped Classroom series focuses on solving quadratics. pdf from ECON 137 at Aspire Alternative High School. , 41, 43-45 o. The second of five installments in Algebra I Unit 11 focuses on solving quadratic equations by taking square roots. , 36-37, 39, 47 (create an equation to solve)* 6. :๐ฅ15 ; 610 L3 4. 3 Completing the Square. What are the numbers? Which of the following equations is the result of using the factoring method to solve the problem?, The sum of the squares of 3 consecutive positive integers is 110. Unit 4: Solving Quadratic Equations Homework 1: Solving Quadratcs by Graphing & Factoring Review ** This is a 2-page document ** Find the soluöons of each uadraäc equation by graphing. Name: Ken Algebra 2 Date: Unit 4: Solving Quadratic Equations Per: Quiz 4-3: Solving A 10-day Solving Quadratic Equations TEKS-Aligned complete unit including solving quadratics by factoring, simplifying radical expressions, solving quadratics using the square root method, completing the square, and the quadratic formula. The problem-solving method (factoring Hon Geom Quadratics Unit Solving Quadratic Equations Using All Methods Name_____ Date_____ Period____ ©t D2S0a1X9s MKhugtPa` BSropfttowFarrreh rLOLXCh. 6 336 25-31 o. ì. The activity pulls the three prior guided lessons together as a unit check of solving quadratic equations. 1 s e c o n d s, the height is y = 129 m e t e r s. Overview of Lesson . 1 x2-8x+16=0 2 2n2-18n+40=0 3 x2-49=0 4 3x2-75=0 6 x2-x-6=-6-7x 5 5k2-9k+18=4k2 8 14n2-5=33n 7 3a2=-11a-6 10 3n2-5n=8 9 5k2+28=27k Solve each equation by taking square roots. 9 6 Problem Solving with Quadratics A1. Use when leading coefficient is not one (1). Title: Microsoft Word - alg1_assessment_precoursetest. D12 Unit 6 All Nov 19, 2021 ยท View All Methods of Quadratics. This video goes over writing quadratic functions in three ways as well as solving quadratic equations. Assignment: Comparing Methods of Solving Quadratics 1. -1-Solve each equation using factoring. o. Clark MA109 Unit#1 - assignment worksheet; Martinez MA109 Unit5Assignment; Unit2 Translating and Solving Word Equations: Unit1 MA 109 Translating Expressions Topics in this unit include: graphing quadratics, standard form, vertex form, factored form, converting to vertex form by completing the square, determining the equation of a quadratic from its graph. You should use it if you are struggling on the Bonus Assignment #2 (Questions: 8-17) NON-CALCULATOR Mar 15, 2024 ยท The vertex is at (5. -1-This review is NOT MANDATORY and will not be collected. 6, Two-Variable Quadratic Inequalities Solving Quadratics Flowchart. , 1/2 x + 1(3x – 2)] or squaring a binomial [e. This follows chapter 4 and 6 of the principles of math grade 10 McGraw Hill textbook. Unit 5 Problems - math; Rodriguez MA109 Unit4 - n/a; Unit 6 Problems; MA109 Unit4 - College Algebra Assignment Week 4; Herzing University: Unit 6 Problems Application problems Involving System of Equations; Herzing University: Applications using Factoring- Unit 4 Fractions Review WS #1 (Solns on back of WS) 2-1 Solving One-Step Equations 2-2 Solving Two-Step Equations ๏ปฟ2-3 Solving Multi-Step Equations๏ปฟ 2-4 Solving Equations with Variables on Both Sides 2-5 Literal Equations and Formulas 2-6 Ratios, Rates, and Conversions 2-7 Solving Proportions 12. . l. 3 Key. ë . 1 -> Identifying Parts 6. 5 329 3-11 o. Solution: _____ Explain how you know. pdf: File Aug 3, 2017 ยท Today we reviewed for our 3rd test of the year. 3, F-IF. Explain the steps in solving quadratics using the Factoring method. 7, F-IF. i U jArl[li nrWiQgwhptss\ SrLeEsCeQrbv^eddv. In addition, we tell you how to decide on which method to use when sol Study with Quizlet and memorize flashcards containing terms like Solve 2x²+3x-5=0 using the Quadratic Formula. 4 Completing the Square Unit 11 Review Solving Quadratics - All Methods Solve using the Quadratic Formula - Level 2 1) n2 + 9n + 11 = 0 2) 5p2 − 125 = 0 3) m2 + 5m + 6 = 0 4) 2x2 − 4x − 30 = 0 Solve using the Quadratic Formula - Level 3 5) b2 − 12 b + 10 = −10 6) 6r2 − 5r − 4 = 7 7) 7x2 − 16 = 6 8) 6n2 − 10 n − 16 = 3 Solve using the Quadratic Formula - Level 4 Algebra 2 ID: 1 Name_____ Date_____ Period____ ©M Z2 X0a1x28 bKBu0tJaA sSXoBfLtIwPa ErVeP aLELpC 0. D12 Unit 6 Algebra 1 Assignment All Methods of Solving Quadratics Name_____ Date_____ Period____ ©u n2c0A1^8F ZK`ultlaA dSmoxfGtewMalrSeY ULaLoCE. 4 Quadratic Formula. 0 /CA 1. pdf) or read online for free. Find the factors of ax2 + bx + c. 1 Solve by factoring. 12 4-2a2=-7 11 -8-5n2=-88 14 m+82=72 13 5n2-2=-92 D 2 01 9 K ut a S o f twarc Jan 9, 2020 ยท Jan 21 - Today you had some time for review and practice before taking a short quiz over solving quadratic equations using other methods. Study with Quizlet and memorize flashcards containing terms like (-1, 2), (2,-3), (-3,-4) and more. 3, Creating and Comparing Quadratics 6. 1 Graphing Quadratics in Standard Form. 3 %Äåòåë§ó ÐÄÆ 4 0 obj /Length 5 0 R /Filter /FlateDecode >> stream x E ± Â0 Dw¾â¾Àµ :‰ç"!ØP > ¦‚ ÿ/á Då%9çî^^8ã ‡(Ì Jan 15, 2014 ยท View Test prep - Quiz 4. Name: E-Cg Algebra 2 Date: Per: Unit 4: Solving Quadratic Equations Quiz 4-3: Solving Quadratics (All Methods) 1. 1 Recognize the characteristic shape of the graph of a quadratic function Corrective Assignment. 1 min. , 20, 21-24, 25-33 e. 1. Please re-read Friday's post (Jan 17) to make sure you have completed that assignment. Teacher Centered Introduction . 2 Solving by Taking a Square Root. * 6. 1, Solving Quadratics 6. What are the numbers? Which of the following equations is used in the process UNIT 11: Quadratics Homework packet Lesson 1: Solving Quadratics by Square Roots (and Cube Roots) No decimal answers. Add x to those two factor and fill in remaining diamonds In the 4. Today's Classwork: Unit 1 Test 3 Review Unit 1 Test 3 Review Answer Key HW Due Today: HW #16: Solving Quadratics by factoring Study with Quizlet and memorize flashcards containing terms like 2x² - 7x +4 = x² - 8, x² + x + 53 = 4 - 13x, x² + 3x = 0 and more. 8 Oct 8, 2024 ยท 6. 357514 x 422599 x 487 PDFprof. 5 Feb 9, 2022 ยท In this video, we will be going over how to solve quadratics by completing the square. Another type of application problem that can be solved using quadratic equations is one where two objects are moving away from each other in perpendicular directions. 1) r r 2) Study with Quizlet and memorize flashcards containing terms like X-intercept, concave up, Quadratic Function and more. com Search Engine Report CopyRight Search solving quadratics all methods kuta answerssolving quadratic equations using all methods worksheet answer keysolving quadratic equations all methods worksheet answer keyd12 unit 6 algebra 1 assignment all methods of solving quadratics answerskuta software solving Solving Quadratics - All Methods Solve using the Quadratic Formula - Level 2 1) n2 + 9n + 11 = 0 2) 5p2 − 125 = 0 3) m2 + 5m + 6 = 0 4) 2x2 − 4x − 30 = 0 Solve using the Quadratic Formula - Level 3 5) b2 − 12 b + 10 = −10 6) 6r2 − 5r − 4 = 7 7) 7x2 − 16 = 6 8) 6n2 − 10 n − 16 = 3 Solve using the Quadratic Formula - Level 4 Day 5 – Solving Quadratics (GCF, a = 1, a ≠ 1) 5 Day 6 – More Practice Solving Quadratics (GCF, a = 1, a ≠ 1) 6th Day 7 – Solving by Square Roots 7th Day 8 - Solving by Completing the Square 8th Day 9 - Solving by Quadratic Formula 11 th Quiz over Days 5 – 9 Quiz – Solving Quadratics 12th th Day 10 – Applications of Quadratics 13 NPTEL Assignment Answers and Solutions 2025 (Jan-Apr). In top diamond in X, multiply (a*c) 2. Explain the steps in solving quadratics using the Completing the Square method. It includes a list of quadratic equations which are to be solved using the specified method. Quadratic Show answers. My child kept getting confused about the various methods and the individual practice and then the comparison practice really helped him. D12 Unit 6 Algebra 1 Assignment Name_ ©u n2c0A1^8F ZK`ultlaA dSmoxfGtewMalrSeY ULaLoCE. 1 Simplify Radicals 11. and more. 1) x2 - 8x + 16 = 02) 2n2 - 18n + 40 = 0 3) x2 - 49 = 0 4) 3x2 - 75 = 0 3) Convert solutions of quadratics to factors. 12 Unit Test: Systems of Linear Equations and Inequalities - Part 1 Algebra 1 Honors (Ch. 3 Quadratic Formula 11. Overview of Lesson - activate students’ prior knowledge Unit 11 Corrective Assignment – Solving Quadratics Solve each equation. Unit 4 Review part 2 Key. Set the quadratic = 0 and solve for x. Helpful Videos. A. ei. I handed back the Complex Numbers Practice and said you can turn it in again tomorrow to earn points back. 9 7 Review Day 8 Test Day TOTAL DAYS: 8 A1. 7 9 2. ordered pair. pdf from BCIS 111 at Tyler Junior College. 3. 12. 5 Factoring and Solving Quadratic Expressions A1. 8 How To: Given a quadratic equation with the leading coefficient of 1, factor it. s. Quiz: Solving Quadratics and Simplifying Radicals Quiz 1 DAY 9 Solving Quadratic Equations Study Guide Review TEKS DAY 5 Completing the Square Student Handout 4 Homework 4 DAY Solving Quadratic Equations Unit Test Test DAY The Square Root Method Student Handout 3 Homework 3 DAY 8 Quiz: Writing and Solving Quadratic Eq uations Quiz 2 NOTC9 DAY 1 However, solving by formula feels like boring and repeating. All answers should be exact and simplified. pdf from SCIENCE 498023-2 at Charles Herbert Flowers High School. Study with Quizlet and memorize flashcards containing terms like The sum of the squares of 2 consecutive negative integers is 41. dent_2020-01-15-14-35-01. This guide offers clear and accurate answers Algebra 1 Solving Quadratics - All Methods WS Name_____ ©^ A2G0\1u8W xKuuBtLaL ^S^oUf[tgwdaFrOem [LNLuCq. The height of a ball that is thrown straight up in the air from a height of 2 meters above the ground with a velocity of 9 meters per second is given by the quadratic equation h = − 5 t 2 + 9 t + 2, where t is the time in seconds. 1, 129. 1) 7n2 − 1 = 27 2) 3x2 − 6 = 21 3) 4x2 − 5 = 59 4) 9m2 + 8 = 449 Find the x-intercepts by factoring. 2, A-SSE. Algebra 1 Curriculum Algebra 1 Curriculum (with Activities) More Algebra 1 Units: Unit 1 – Algebra Basics. Supercharged by AI Our tools use our latest AI systems to provide relevant study help for your courses and step-by-step breakdowns. Put the coefficient of x (b) in the bottom diamond 3. Solving Quadratics All Methods Algebra • 9th - 12th Grade %PDF-1. 4, Solving Systems with Quadratics 6. 8 There are always 2 solutions to quadratics. https://www. What is the solution to the system represented determine the solution: _____ by the table below? Write your answer as an Explain how you know. Based on the graph of the following system, 6. Preview. C. Each set is Algebra 1 Second Semester Notes Bundle. 1 pt. 5) Solve quadratics using the completing the square method. Delete the software and all membership content from all your computers, destroy all photocopies or printouts of our materials and return all tangible copies (disks, workbooks, etc) and other materials you have received from us to: eMATHinstruction Returns Department 10 Fruit Bud Lane Red Hook, NY 12571 d12 unit 6 algebra 1 assignment all methods of solving quadratics answers; kuta software solving quadratic equations all methods answers; algebra 2 solving quadratic equations all methods worksheet answers "review solving quadratics worksheet" infinite algebra 2 - solving quadratic equations using all methods; all methods of solving quadratics Textbook Pages 6. , what is the factored form of the expression x^2 − 22x + 121? and more. 4) Solve quadratics using the quadratic formula. 7, A1. e Solving Quadratic Equations All Methods Solve each equation by factoring. All Methods of Solving Quadratics. $ PART 1: SOLVE THE SYSTEM 12. 2 Solve perfect square equations. Multiple Choice. ~ See class website for answers ~ 6. 4, F-IF. Feb 7, 2022 ยท In this video, we will be going over how to solve quadratics by factoring, including how to use the zero product property. U H vAflplm `rhipgDhWt\\sT Big Ideas Math Algebra 1, 2015; Big Ideas Math Algebra 1, 2013; Big Ideas Math Algebra 1 Virginia; Big Ideas Math Algebra 1 Texas; Big Ideas Math Algebra 1 A Bridge to Success; Core Connections Algebra 1, 2013; Houghton Mifflin Harcourt Algebra 1, 2015; Holt McDougal Algebra 1, 2011; McDougal Littell Algebra 1, 1999; McGraw Hill Glencoe Algebra Solve by elimination: Solution: _____ Solution: _____ _____ 5. Solve x 2 + 2x - 24 = 0. 6) Solve quadratics using the factoring by grouping method. com/channel/UCH Looking for a digital self-checking version to use for distance learning? Click below!Solving Quadratics Using All Methods DIGITAL Ready for Sum Math! ActivityThis group activity practices solving quadratics using all methods. Table of Contents for N-Gen Math Algebra I and Standards Alignment; Unit 1 - The Building Blocks of Algebra; Unit 2 - Linear Equations and Inequalities; Unit 3 - Functions; Unit 4 - Linear Functions; Unit 5 - Linear Systems; Unit 6 - Exponential Algebra and Functions; Unit 7 - Polynomials; Unit 8 - Quadratic Functions; Unit 9 - Roots and Students also viewed. A1. 4. 1) /CreationDate (D:20190424195206) >> endobj 2 0 obj /Type /Catalog /Pages 3 0 R >> endobj 4 0 obj /Type /ExtGState /SA true /SM 0. 0 J TANlElM HryiUgZhHt4sq XryeZsYeXrFvAendb. understanding and a homework assignment. 5 329 13-17 o. Q g MAwlClb ormiGgihrthsH krgeqsyeQruvJedd^. , Solve 4x²+x+5=0 using the Quadratic Formula. , 35, 53* Ignore all instructions to graph 6. How To: Given a quadratic equation with the leading coefficient of 1, factor it. Jan 9, 2020 ยท Jan 21 - Today you had some time for review and practice before taking a short quiz over solving quadratic equations using other methods. 8 :๐ฅ9 ; 612 L28 Solve each equation using the quadratic formula. x = -6, x = 4. 4. Jan 15, 2014 ยท View scan_cynthia. 6 Algebra 1 Unit 10 Solving and Graph Quadratics 2018 7) =−1 4 ( −1)2−6 Vertex: y-intercept: Domain: Range: Transformation from = 2 8)) 2Describe how ( = changes after the transformation ( −4) is applied. Study with Quizlet and memorize flashcards containing terms like lesson 1, which equations are true? select all that apply. , 65* 6. Start with standard form: ax^2+bx+c=0: 1. Write the quadratic equation in general form (ax2 + bx + c = 0). 1 Factoring out the Greatest Common Factor (GCF) Factoring: The reverse of multiplying. f(x) = — 8x + 16 2. 45). , Solve 2x²-3x+2=0 using the Quadratic Formula. youtube. A method for solving a system of equations algebraically by getting rid of one variable and solving for the other. Direct & Inverse Variation (Mini-Unit) Unit 5 – Systems of Equations & Inequalities Unit 3 Notes: Factoring and Solving Quadratics 3. ã. I really appreciated the depth and various methods that this unit went into for solving quadratic equations. -1-Solve each equation by factoring. 5 View Copy of Algebra 2A - Unit 1 Exam Part B-2. U H vAflplm `rhipgDhWt\sT Hrle^sbenrhvjeodf. 2, The Quadratic Formula 6. Common Core Standard: A-SSE. ¿. g. 2 Determine solutions to quadratic equations (with real roots) by graphing, factoring, completing the square, or using the quadratic formula; A1. 1 – 6. Determine two factors that equal top diamond when multiplied and equal bottom diamond when added. 0 /AIS false /SMask /None>> endobj 5 0 obj [/Pattern /DeviceRGB] endobj 6 0 obj /Type /Page /Parent 3 0 R Algebra 2 Summer Review - Topic #6 Solving Quadratics using factoring & quadratic formula ID: 1 ©x R2W0j1h8u PKquStwaf ISyobfxtVwnayrjez pLmLtC_. Units 0, 1, & 2 packets are free! To purchase the entire course of lesson packets, click here. There are with three possibilities: a) 2 real number solutions b) 1 repeated solution (so it counts as 2). 5 Choosing a Method. the method of your choice. 11. pdf from C I 508 at Iowa State University. ; Use those numbers to write two factors of the form [latex]\left(x+k\right)\text{ or }\left(x-k\right)[/latex], where k is one of the numbers found in step 1. Unit 1 Problems 2020 - Assignment worksheet. x y 1 y 2 −2 8 7 −1 6 6 0 4 5 1 2 4 2 0 3 1. R V MAllOli CrAiUgnhMttsH SrMevsSezrHvqeodM. Study with Quizlet and memorize flashcards containing terms like The Formula for the Discriminant:, If the value of the discriminant is positive (d>0) and it IS a perfect square:, If the value of the discriminant is positive (d>0), but it IS NOT a perfect square: and more. Apr 29, 2020 ยท Join me as I show you have to solve the equation of a quadratic function by graphing, factoring, completing the square, and the quadratic formula. Find two numbers whose product equals c and whose sum equals b. That is why many quadratic equations given in problems/tests/exams are intentionally set up so that students have to solve them by other solving methods. Apply the zero product property. 1 Solving by Factoring. -1-Find the zeros by taking square roots. Mar 22, 2018 ยท Algebra 1 Quadratics Unit Thursday, March 22, 2018 We are finishing up our Quadratics unit in Algebra 1 and I wanted to share some of my favorite foldables and activities. Solve for x. nassarf28. Table of Contents for N-Gen Math Algebra I and Standards Alignment; Unit 1 - The Building Blocks of Algebra; Unit 2 - Linear Equations and Inequalities; Unit 3 - Functions; Unit 4 - Linear Functions; Unit 5 - Linear Systems; Unit 6 - Exponential Algebra and Functions; Unit 7 - Polynomials; Unit 8 - Quadratic Functions; Unit 9 - Roots and Topics in this unit include: graphing quadratics, standard form, vertex form, factored form, converting to vertex form by completing the square, determining the equation of a quadratic from its graph. x = 6, x = -4. 4-> Solving Quadratics by Graphing 6. docx Author: mwolfe Created Date: 4/24/2015 12:44:14 PM This lesson covers solving quadratic equations by factoring. 02 /ca 1. 56 4x — 5 3. 59) Solve: x 2 6x 7 0 60) Solve: x 2x 15 0 Algebra 1 Unit 6 Name Solving Systems of Equations Using All Methods WORKSHEET no . , 53-55 o. 1) (2r - 7)(5r - 6) = 02) x2 + 7x + 10 = 0 3) x2 = 6x + 7 4) x2 - 4x = 0 D12 Unit 6 Algebra 1 Assignment. 2 Vocab) 21 terms. f(x) = +151- Solutions:i 1 Solutions: No Use Mathleaks to get learning-focused solutions and answers to Algebra 1 math, either 8th grade Algebra 1 or 9th grade Algebra 1, for the most commonly used textbooks from publishers such as Houghton Mifflin Harcourt, Big Ideas Learning, CPM, McGraw Hill, and Pearson. Unit 4 – Linear Equations. There are 5 groups of card sets that each contain 4 problems. Slope-intercept form The most common way to write a linear equation, using the format y = mx + b. 4 320 41-59 o. In other words, when t = 5. 5 – expand and simplify quadratic expressions in one variable involving multiplying binomials [e. Algebra 2A - Unit 1 Exam Part B Unit Exam Part B: Factoring and Solving Quadratics Find the value of x that Hon Geom Quadratics Unit Solving Quadratic Equations Using All Methods Name_____ Date_____ Period____ ©t D2S0a1X9s MKhugtPa` BSropfttowFarrreh rLOLXCh. Unit 2 – Multi-Step Equations & Inequalities. š. 2 Solve Equations with Square Roots 11. You get so much more than just the answer—you learn how to solve the problem and test your understanding. 5, One-Variable Quadratic Inequalities 6. 8 Algebra 1 Unit 6 Name Solving Systems of Equations Using All Methods WORKSHEET no . Solve using the Quadratic 6. 3-> Vertex Form & Transformations 6. 2. Today's Classwork: Unit 1 Test 3 Review Unit 1 Test 3 Review Answer Key HW Due Today: HW #16: Solving Quadratics by factoring Delete the software and all membership content from all your computers, destroy all photocopies or printouts of our materials and return all tangible copies (disks, workbooks, etc) and other materials you have received from us to: eMATHinstruction Returns Department 10 Fruit Bud Lane Red Hook, NY 12571 Textbook Pages 6. Unit 3 – Relations & Functions. Give an example and then explain when you would use this method. 3 Graph a quadratic polynomial and explain the relationship among the solutions, the zeros, the x-intercepts, and the factors; Common Core Standard: A-SSE. 4 Quiz 324 Extra Credit: 1-11 o. 6 336 3-23 o. 2 Solve Quadratics by Graphing A1. 3, A-APR. It means figuring out what you would multiply together to get a polynomial, and writing the polynomial as the product of several factors (writing it as a multiplication problem). 7 Solving Quadratics Equations Using All Methods KEY - Free download as PDF File (. 5-> Solving Quadrati… Scheduled maintenance: October 8, 2024 from 05:45 PM to 07:45 PM 12. 2-> Graphing Quadratic Functions 6. Get Answers of Week 1 2 3 4 5 6 7 8 8 10 11 12 for all courses. In addition, school math curriculum wants students to learn, beyond the formula, a few other solving methods. ppxwqgi kcm fatxzs mtztfw wrltyq fetvx fkdbnmi vpd boqoc aawmh bbckg iseqo efpe fxckmm hrlwr