Lesson 3: Write and Solve Equations Using Multiplication or Division6.AT.8

I can…

I can solve one-step multiplication and division equations using inverse operations.

Key words

• Solve Multiplication and Division Equations — Use inverse multiplication or division to isolate the variable.
• Inverse operation — Two math actions that undo each other, like × and ÷.
• Multiply — To add equal groups again and again.
• Divide — To split into equal groups.
• Isolate — To get the letter by itself on one side.
• Coefficient — The number in front of a letter, like the 3 in 3x.
• Solution — A number that makes the equation or inequality true.
• Division Property of Equality — Dividing both sides by the same nonzero number keeps an equation balanced.
• Multiplication Property of Equality — Multiplying both sides by the same number keeps an equation balanced.

Steps

1. Solve 3x = 21. This means 3 times x equals 21.
2. The inverse of multiplying by 3 is dividing by 3.
3. I divide both sides by 3: 3x ÷ 3 = 21 ÷ 3.
4. That leaves x = 7. Check: 3 × 7 = 21. True!

Try it

Solve: y / 4 = 9

Check your answer

y = 36

Multiply both sides by 4: y = 9 × 4 = 36. Check: 36 / 4 = 9 ✓

Sentence starter

I know ___ because ___.

Goal: I can explain my steps using the words inverse operation, multiply, divide, and isolate.