Question

How do you subtract fractions?

Answer 1

When subtracting factions you need to have both denominators be the same

Let's use an example. . .

Explanation:

1.
`(3)/(4) -(1)/(3)`

We can see here our denominators aren't the same. To get them to be equal, we have to multiply them by each other.

2.
`(3)/(3) \cdot(3)/(4) -(1)/(3)\cdot (4)/(4)`

Notice that when we do multiply, we also have to multiply the top! What's done to the bottom needs to be done to the top.

3. Let's go into the multiplication:

On the left side

Numerator: 3 · 3 = 9

Denominator: 3 · 4 = 12

On the right side

Numerator: 4 · 1 = 4

Denominator: 4 · 3 = 12

4.
`(9)/(12) -(4)/(12)`

Now all we do here is subtract the numerator. The denominator does not get subtracted, it stays the same.

5.
`(9)/(12) -(4)/(12) =(5)/(12)`

Tada!

The most important thing to remember is

1. The denominator needs to be the same, multiply each other to get a like term
2. What's multiplied at the bottom must also be multiplied at the top
3. When you get to subtracting, the denominator doesn't subtract, it stays the same

Answer 2

Make sure the bottom numbers (the denominators) are the same.
Subtract the top numbers (the numerators). Put the answer over the same denominator.
Simplify the fraction (if needed).