1. How can two different equations have the same solution?? x+7= 25 has the same solution as the equation x + 14 = 32

2. In this lesson you will learn that properties of equality apply to equations containing unknown values by making connections to real numbers

3. Let’s Review 9 = 9 9 – 6 = 9– 6 3 = 3

4. 5 = 5 5 + 7 = 5 + 7 12 = 12

5. What does “solution” mean in math? x-2=0 2 is a solution

6. A Common Mistake Forgetting properties of equality apply to algebraic expressions

7. Core Lesson x+5 = 10 and x+15 = 20 x+5 + 10 = 10 + 10 x+15 = 20

8. x + 7 = 14 and x – 2 = 5 x + 7 - 9 = 14- 9 x – 2 = 5

9. In this lesson you have learned how to tell if equations have the same solution by using the principles of equality

10. Guided Practice Do the pairs of algebraic expressions have the same solution? x = 7 and x + 8 = 15 x + 4 = 6 and x + 2 = 8

11. Extension Activities How would you know that two expressions do not have the same solution? Show your work and provide an example

12. Using the mathematical definition of solution, what is the solution for x + 2 = 5? Is it the same solution as x + 6 = 9? Show your work.

13. Describe the steps you would take to determine if X + 7 =14 and x -3= 4 have the same solution. Complete the problem and show your work.

14. Quick Quiz Do x + 7 = 4 and x + 10 = 7 have the same solution? Do x + 9 = 20 and x + 1 = 12 have the same solution?