Step by step
The question
Question: work out −1/2 ÷ 3/4.
−12 ÷ 34
1 Flip and multiply
Dividing by a fraction is the same as times its flip.
Keep the first number.
Change divide to times.
Turn the second fraction upside down.
÷ 34 → × 43
So 3/4 becomes 4/3, and divide becomes times.
= −12 × 43
2 Cancel first
Minus times plus is minus.
Before we multiply, we make the numbers smaller.
4 on top and 2 at the bottom both divide by 2.
A top and a bottom divided by the same number: the answer stays the same.
4 and 2: ÷ 2 → 2 and 1
So we multiply smaller numbers.
= −11 × 23
3 Multiply tops and bottoms
To multiply fractions, we do top times top, and bottom times bottom.
= −1 × 21 × 3
1 times 2 is 2.
1 times 3 is 3.
= −23
Can we make it simpler?
No number goes into both 2 and 3, except 1.
So it stays like this.
simplest ✓
So the answer is −2/3.
Let's look back.
First: flip and multiply.
Then: cancel first.
Last: multiply tops and bottoms.
Answer
= −23