math help

What is 88/15 + 7/9?

What is 88/15 + 7/9?

Here's how to add

88
15
+
7
9

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 9, and get 792, then we multiply 15 by 9 and get 135.

88/15 times 9

Now for the second term. You multiply 7 by 15, and get 105, then multiply 15 by 9 and get 135.

7/9 times 15

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

792
135
+
105
135

Step 2

Since our denominators match, we can add the numerators.

792 + 105 = 897

That gives us the sum, which is

897
135

Step 3

Now, do we need to simplify this fraction?

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

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:

897
135
÷ 3 =
299
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 5...

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

No good. So next you try the next prime number, which is 11...

No good. So next you try the next prime number, which is 13...

No good. So next you try the next prime number, which is 17...

No good. So next you try the next prime number, which is 19...

No good. So next you try the next prime number, which is 23...

No good. So next you try the next prime number, which is 29...

No good. So next you try the next prime number, which is 31...

No good. So next you try the next prime number, which is 37...

No good. So next you try the next prime number, which is 41...

No good. So next you try the next prime number, which is 43...

No good. So next you try the next prime number, which is 47...

No good. 47 is larger than 45. So we're done reducing.

And we're done! Here's the final answer to 88/15 + 7/9

88
15
+
7
9
=
299
45
© 2014 Randy Tayler