math help

What is 88/15 + 9/12?

What is 88/15 + 9/12?

Here's how you add

88
15
+
9
12

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. 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 88 by 12, and get 1056, then we multiply 15 by 12 and get 180.

88/15 times 12

Do the same for the second term. We multiply 9 by 15, and get 135, then multiply 15 by 12 and get 180.

9/12 times 15

So now our fractions look like this:

1056
180
+
135
180

Step 2

Since our denominators match, we can add the numerators.

1056 + 135 = 1191

Now we have an answer.

1191
180

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...

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

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

1191
180
÷ 3 =
397
60

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...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

Nope. Try the next prime number, 53...

Nope. Try the next prime number, 59...

Nope. Try the next prime number, 61...

No good. 61 is larger than 60. So we're done reducing.

Congratulations! Here's your final answer to 88/15 + 9/12

88
15
+
9
12
=
397
60
© 2014 Randy Tayler