math help

What is 99/7 + 3/12?

What is 99/7 + 3/12?

This is how you add

99
7
+
3
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 99 by 12, and get 1188, then we multiply 7 by 12 and get 84.

99/7 times 12

Now for the second term. You multiply 3 by 7, and get 21, then multiply 7 by 12 and get 84.

3/12 times 7

This gives us a new problem that looks like so:

1188
84
+
21
84

Step 2

Since our denominators match, we can add the numerators.

1188 + 21 = 1209

That gives us an answer of

1209
84

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:

1209
84
÷ 3 =
403
28

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...

No good. 29 is larger than 28. So we're done reducing.

Congratulations! Here's your final answer to 99/7 + 3/12

99
7
+
3
12
=
403
28
© 2014 Randy Tayler