math help

What is 4/5 - 8/12?

What is 4/5 - 8/12?

Here's how to subtract 8/12 from 4/5:

4
5
8
12

Step 1

We can't subtract two fractions with different denominators. So you need to get a common denominator. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 4 by 12, and get 48.

Then we multiply 8 by 5, and get 40.

Next we give both terms new denominators -- 5 × 12 = 60.

So now our fractions look like this:

48
60
40
60

Step 2

Since our denominators match, we can subtract the numerators.

48 − 40 = 8

So the answer is:

8
60

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

To find out, we try dividing it by 2...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

8
60
÷ 2 =
4
30

Let's try dividing by 2 again...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

4
30
÷ 2 =
2
15

Let's try dividing by 2 again...

Nope! So now we try the next greatest prime number, 3...

No good. 3 is larger than 2. So we're done reducing.

There you have it! The final answer is:
4
5
8
12
=
2
15