2. to one side of an equation, When you do something

3. you have to do exactly the same thing to the other side.

4. To solve an equation means to find every number that makes the equation true.

5. In the equation, x is the number to get 15. you add to 7

6. What is the number? 8, of course.

7. What is the number? 8, of course.

8. What is the number? 8, of course. So we would write the solution,.

9. In some equations, the solution is obvious.

10. But in other equations, the solution is not so obvious.

11. Many times we need a way to solve equations.

12. To understand one way, we can work backwards. Start with a solution,

13. And create another equation by changing both sides.

14. To solve that equation, you can just undo what you did.

18. Now you see how easy solving these types of equations can be.

19. If you had started with the solution, what would you have done to get this equation?

20. And if you subtracted 12 from both sides, what would you do to get the original solution?

21. Right! add 12 to both sides. You would need to

22. think about what you need to do to get the variable by itself on one side of the equation. As you solve these equations,

23. Think about what you need to do isolate the variable.

24. 1. 2. 3. 4.

25. 5. 6. 7.