Solving Equations with Variables on Both Sides Page 1 of 4
Review of Two-Step Equations
In order to understand the equations in this lesson, it's important that you understand how to solve one-step equations and two-step equations. Equations with variables on both sides involve a few more steps, so I want to make sure you understand the simpler equations first before moving forward. Let's say you have the equation below:
This equation means that if you multiply a "mystery number" x by 5 and then subtract 1, the answer will be 19. To solve for x, you need to work your way backwards to get x by itself. Since the subtraction was done last, that's the first thing that needs to be undone. How do you cancel out subtracting 1? You need to use the inverse operation and add 1 to both sides. Remember to always do the same thing on BOTH sides of the equation to keep things balanced.
Remember to use inverse operations to work your backwards and get x by itself. Undo addition and subtraction before you undo multiplication and division.
Now we're left with the equation 5x = 20. This means that when you multiply x by 5, you get 20. How do you undo multiplying by 5? You use the inverse operation and divide both sides by 5.
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