Grade 8 Mathematics Module 4, Topic A, Lesson 7

NYS COMMON CORE MATHEMATICS CURRICULUM
Lesson 7
8β€’4
Lesson 7: Classification of Solutions
Classwork
Exercises
Solve each of the following equations for π‘₯.
1.
7π‘₯ βˆ’ 3 = 5π‘₯ + 5
2.
7π‘₯ βˆ’ 3 = 7π‘₯ + 5
3.
7π‘₯ βˆ’ 3 = βˆ’3 + 7π‘₯
Lesson 7:
Classification of Solutions
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NYS COMMON CORE MATHEMATICS CURRICULUM
Lesson 7
8β€’4
Give a brief explanation as to what kind of solution(s) you expect the following linear equations to have. Transform the
equations into a simpler form if necessary.
4.
11π‘₯ βˆ’ 2π‘₯ + 15 = 8 + 7 + 9π‘₯
5.
3(π‘₯ βˆ’ 14) + 1 = βˆ’4π‘₯ + 5
6.
βˆ’3π‘₯ + 32 βˆ’ 7π‘₯ = βˆ’2(5π‘₯ + 10)
7.
1
2
(8π‘₯ + 26) = 13 + 4π‘₯
Lesson 7:
Classification of Solutions
This work is derived from Eureka Math β„’ and licensed by Great Minds. ©2015 Great Minds. eureka-math.org
This file derived from G8-M4-TE-1.3.0-09.2015
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Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
NYS COMMON CORE MATHEMATICS CURRICULUM
8.
Write two equations that have no solutions.
9.
Write two equations that have one unique solution each.
Lesson 7
8β€’4
10. Write two equations that have infinitely many solutions.
Lesson 7:
Classification of Solutions
This work is derived from Eureka Math β„’ and licensed by Great Minds. ©2015 Great Minds. eureka-math.org
This file derived from G8-M4-TE-1.3.0-09.2015
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This work is licensed under a
Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
Lesson 7
NYS COMMON CORE MATHEMATICS CURRICULUM
8β€’4
Lesson Summary
There are three classifications of solutions to linear equations: one solution (unique solution), no solution, or
infinitely many solutions.
Equations with no solution will, after being simplified, have coefficients of π‘₯ that are the same on both sides of the
equal sign and constants that are different. For example, π‘₯ + 𝑏 = π‘₯ + 𝑐, where 𝑏 and 𝑐 are constants that are not
equal. A numeric example is 8π‘₯ + 5 = 8π‘₯ βˆ’ 3.
Equations with infinitely many solutions will, after being simplified, have coefficients of π‘₯ and constants that are the
same on both sides of the equal sign. For example, π‘₯ + π‘Ž = π‘₯ + π‘Ž, where π‘Ž is a constant. A numeric example is
6π‘₯ + 1 = 1 + 6π‘₯.
Problem Set
1.
Give a brief explanation as to what kind of solution(s) you expect for the linear equation 18π‘₯ +
1
= 6(3π‘₯ + 25).
2
Transform the equation into a simpler form if necessary.
2.
Give a brief explanation as to what kind of solution(s) you expect for the linear equation 8 βˆ’ 9π‘₯ = 15π‘₯ + 7 + 3π‘₯.
Transform the equation into a simpler form if necessary.
3.
Give a brief explanation as to what kind of solution(s) you expect for the linear equation 5(π‘₯ + 9) = 5π‘₯ + 45.
Transform the equation into a simpler form if necessary.
4.
Give three examples of equations where the solution will be unique; that is, only one solution is possible.
5.
Solve one of the equations you wrote in Problem 4, and explain why it is the only solution.
6.
Give three examples of equations where there will be no solution.
7.
Attempt to solve one of the equations you wrote in Problem 6, and explain why it has no solution.
8.
Give three examples of equations where there will be infinitely many solutions.
9.
Attempt to solve one of the equations you wrote in Problem 8, and explain why it has infinitely many solutions.
Lesson 7:
Classification of Solutions
This work is derived from Eureka Math β„’ and licensed by Great Minds. ©2015 Great Minds. eureka-math.org
This file derived from G8-M4-TE-1.3.0-09.2015
S.25
This work is licensed under a
Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.