Lesson 2 of 8
Solving One- and Two-Step Equations
An equation has an equals sign, and your job is to get the variable alone on one side. The golden rule: whatever you do to one side, do to the other side too. That keeps it balanced.
Undo with the opposite
- ●Addition is undone by subtraction
- ●Subtraction is undone by addition
- ●Multiplication is undone by division
- ●Division is undone by multiplication
- 1Solve 2x + 5 = 13
- 2Undo the +5 first: subtract 5 from both sides, giving 2x = 8
- 3Undo the times 2: divide both sides by 2, giving x = 4
- 4Check: 2(4) + 5 = 8 + 5 = 13, correct
REMEMBER
In a two-step equation, undo addition or subtraction FIRST, then undo multiplication or division. It's the reverse of PEMDAS.
Always check by plugging your answer back into the original equation. If both sides match, you got it.