math help

What is 50/8 - 9/10?

What is 50/8 - 9/10?

Here's how to subtract 9/10 from 50/8:

50
8
9
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 50 by 10, and get 500.

Then we multiply 9 by 8, and get 72.

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

So now our fractions look like this:

500
80
72
80

Step 2

Since our denominators match, we can subtract the numerators.

500 − 72 = 428

So the answer is:

428
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:

428
80
÷ 2 =
214
40

Let's try dividing by 2 again...

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

214
40
÷ 2 =
107
20

Let's try dividing by 2 again...

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

Nope! So now we try the next greatest prime number, 5...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

No good. 23 is larger than 20. So we're done reducing.

There you have it! The final answer is:
50
8
9
10
=
107
20