math help

What is 99/7 + 6/9?

What is 99/7 + 6/9?

This is how you add

99
7
+
6
9

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 99 by 9, and get 891, then we multiply 7 by 9 and get 63.

99/7 times 9

Now for the second term. You multiply 6 by 7, and get 42, then multiply 7 by 9 and get 63.

6/9 times 7

This gives us a new problem that looks like so:

891
63
+
42
63

Step 2

Since our denominators match, we can add the numerators.

891 + 42 = 933

That gives us an answer of

933
63

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:

933
63
÷ 3 =
311
21

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 99/7 + 6/9

99
7
+
6
9
=
311
21
© 2014 Randy Tayler