math help

What is 88/15 + 4/12?

What is 88/15 + 4/12?

Here's how to add

88
15
+
4
12

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 88 by 12, and get 1056, then we multiply 15 by 12 and get 180.

88/15 times 12

Now for the second term. You multiply 4 by 15, and get 60, then multiply 15 by 12 and get 180.

4/12 times 15

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

1056
180
+
60
180

Step 2

Since our denominators match, we can add the numerators.

1056 + 60 = 1116

That gives us the sum, which is

1116
180

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:

1116
180
÷ 2 =
558
90

So far so good... let's try to divide by that number again.

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

558
90
÷ 2 =
279
45

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

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

279
45
÷ 3 =
93
15

So far so good... let's try to divide by that number again.

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

93
15
÷ 3 =
31
5

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 5...

No good. So next you try the next prime number, which is 7...

No good. 7 is larger than 5. So we're done reducing.

And we're done! Here's the final answer to 88/15 + 4/12

88
15
+
4
12
=
31
5
© 2014 Randy Tayler