math help

What is 100/24 - 2/7?

What is 100/24 - 2/7?

Here's how to subtract 2/7 from 100/24:

100
24
2
7

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 100 by 7, and get 700.

Then we multiply 2 by 24, and get 48.

Next we give both terms new denominators -- 24 × 7 = 168.

So now our fractions look like this:

700
168
48
168

Step 2

Since our denominators match, we can subtract the numerators.

700 − 48 = 652

So the answer is:

652
168

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:

652
168
÷ 2 =
326
84

Let's try dividing by 2 again...

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

326
84
÷ 2 =
163
42

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...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

Nope! So now we try the next greatest prime number, 41...

Nope! So now we try the next greatest prime number, 43...

No good. 43 is larger than 42. So we're done reducing.

There you have it! The final answer is:
100
24
2
7
=
163
42