math help

What is 12/13 + 6/7?

What is 12/13 + 6/7?

This is how we add

12
13
+
6
7

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 12 by 7, and get 84, then we multiply 13 by 7 and get 91.

12/13 times 7

Do the same for the second term. We multiply 6 by 13, and get 78, then multiply 13 by 7 and get 91.

6/7 times 13

The problem now has new fractions to add:

84
91
+
78
91

Step 2

Since our denominators match, we can add the numerators.

84 + 78 = 162

The sum we get is

162
91

Step 3

The last step is to reduce the fraction if we can.

To find out, we try dividing it by 2...

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

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. So next you try the next prime number, which is 53...

No good. So next you try the next prime number, which is 59...

No good. So next you try the next prime number, which is 61...

No good. So next you try the next prime number, which is 67...

No good. So next you try the next prime number, which is 71...

No good. So next you try the next prime number, which is 73...

No good. So next you try the next prime number, which is 79...

No good. So next you try the next prime number, which is 83...

No good. So next you try the next prime number, which is 89...

No good. So next you try the next prime number, which is 97...

No good. 97 is larger than 91. So we're done reducing.

And we're done! Here's the final answer to 12/13 + 6/7

12
13
+
6
7
=
162
91
© 2014 Randy Tayler