math help

What is 12/13 + 2/7?

What is 12/13 + 2/7?

This is how to add

12
13
+
2
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 2 by 13, and get 26, then multiply 13 by 7 and get 91.

2/7 times 13

The problem now has new fractions to add:

84
91
+
26
91

Step 2

Since our denominators match, we can add the numerators.

84 + 26 = 110

This yields the answer

110
91

Step 3

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

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...

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

Congratulations! Here's your final answer to 12/13 + 2/7

12
13
+
2
7
=
110
91
© 2014 Randy Tayler