 # What is 7/9 + 9/12? 7 9
+
 9 12

## Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 7 by 12, and get 84, then we multiply 9 by 12 and get 108. Now for the second term. You multiply 9 by 9, and get 81, then multiply 9 by 12 and get 108. This gives us a new problem that looks like so:

 84 108
+
 81 108

## Step 2

Since our denominators match, we can add the numerators.

84 + 81 = 165

So what's the answer so far?

 165 108

## Step 3

Can this fraction be reduced?

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

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

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

 165 108
÷ 3 =
 55 36

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...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

No good. 37 is larger than 36. So we're done reducing.