math help

What is 12/13 + 7/8?

What is 12/13 + 7/8?

Here's how you add

12
13
+
7
8

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 12 by 8, and get 96, then we multiply 13 by 8 and get 104.

12/13 times 8

Do the same for the second term. We multiply 7 by 13, and get 91, then multiply 13 by 8 and get 104.

7/8 times 13

So now our fractions look like this:

96
104
+
91
104

Step 2

Since our denominators match, we can add the numerators.

96 + 91 = 187

So the answer is:

187
104

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...

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...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

Nope. Try the next prime number, 73...

Nope. Try the next prime number, 79...

Nope. Try the next prime number, 83...

Nope. Try the next prime number, 89...

Nope. Try the next prime number, 97...

Nope. Try the next prime number, 101...

Nope. Try the next prime number, 103...

Nope. Try the next prime number, 107...

No good. 107 is larger than 104. So we're done reducing.

Congratulations! Here's your final answer to 12/13 + 7/8

12
13
+
7
8
=
187
104
© 2014 Randy Tayler