What is 72/63 + 4/12?

Here's how we add

Step 1

Can you add yet? Nope! The denominators don't match. We need a common denominator. So next we take both denominators and multiply them. Next, take each numerator and multiply it by the denominator of the other term.

So, we multiply 72 by 12, and get 864, then we multiply 63 by 12 and get 756.

Now for the second term. You multiply 4 by 63, and get 252, then multiply 63 by 12 and get 756.

We now have a new problem, that looks like this:

Step 2

Since our denominators match, we can add the numerators.

864 + 252 = 1116

That gives us the sum, which is

Step 3

Now, do we need to simplify this fraction?

First, we attempt to divide it by 2...

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

Now, try the same number again.

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

Now, try the same number again.

Nope. Try the next prime number, 3...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

Now, try the same number again.

Nope. Try the next prime number, 5...

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

No good. 23 is larger than 21. So we're done reducing.

Congratulations! Here's your final answer to 72/63 + 4/12