math help

What is 4/8 - 1/10?

What is 4/8 - 1/10?

Here's how to subtract 1/10 from 4/8:

4
8
1
10

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 10, and get 40.

Then we multiply 1 by 8, and get 8.

Next we give both terms new denominators -- 8 × 10 = 80.

So now our fractions look like this:

40
80
8
80

Step 2

Since our denominators match, we can subtract the numerators.

40 − 8 = 32

So the answer is:

32
80

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:

32
80
÷ 2 =
16
40

Let's try dividing by 2 again...

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

16
40
÷ 2 =
8
20

Let's try dividing by 2 again...

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

8
20
÷ 2 =
4
10

Let's try dividing by 2 again...

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

4
10
÷ 2 =
2
5

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
8
1
10
=
2
5