Does x = 3 solve 2x + 7 = 13? Show substitution.
Yes; left side = 13
2 × 3 + 7 = 13; compare with 13.
Day 091Testing Equation Solutions
Standards 6.EE.B.5
LEARNING TARGET
I can test a proposed solution by substitution.
01 · LEARN
Build the idea
Replace the variable with the proposed value, compute each side, and compare. A number is a solution only when it makes the original equation true.
Does x = 6 solve 6x + 4 = 40? Show substitution.
Yes; left side = 40
6 × 6 + 4 = 40; compare with 40.
02 · PRACTICE
Your turn
Work in order. Start with the foundations, then build toward explanation and application.
Does x = 3 solve 3x + 4 = 10? Show substitution.
Does x = 4 solve 4x + 4 = 20? Show substitution.
Does x = 6 solve 3x + 6 = 21? Show substitution.
Does x = 6 solve 4x + 4 = 28? Show substitution.
Does x = 3 solve 2x + 7 = 11? Show substitution.
Does x = 4 solve 3x + 3 = 15? Show substitution.
Does x = 4 solve 4x + 7 = 19? Show substitution.
Does x = 3 solve 3x + 2 = 11? Show substitution.
Does x = 5 solve 3x + 2 = 14? Show substitution.
Does x = 5 solve 7x + 2 = 37? Show substitution.
03 · CHECK
Answers and reasoning
Reveal the teacher answer key
- No; left side = 13
3 × 3 + 4 = 13; compare with 10.
- Yes; left side = 20
4 × 4 + 4 = 20; compare with 20.
- No; left side = 24
3 × 6 + 6 = 24; compare with 21.
- Yes; left side = 28
4 × 6 + 4 = 28; compare with 28.
- No; left side = 13
2 × 3 + 7 = 13; compare with 11.
- Yes; left side = 15
3 × 4 + 3 = 15; compare with 15.
- No; left side = 23
4 × 4 + 7 = 23; compare with 19.
- Yes; left side = 11
3 × 3 + 2 = 11; compare with 11.
- No; left side = 17
3 × 5 + 2 = 17; compare with 14.
- Yes; left side = 37
7 × 5 + 2 = 37; compare with 37.