math help

What is 12/13 + 3/7?

What is 12/13 + 3/7?

Here's how to add

12
13
+
3
7

Step 1

Can you add yet? Nope! The denominators don't match. We need a common denominator. So next we take both denominators and multiply them. Next, take each numerator and multiply it by the denominator of the other term.

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

12/13 times 7

Now for the second term. You multiply 3 by 13, and get 39, then multiply 13 by 7 and get 91.

3/7 times 13

We now have a new problem, that looks like this:

84
91
+
39
91

Step 2

Since our denominators match, we can add the numerators.

84 + 39 = 123

Answer:

123
91

Step 3

Now, do we need to simplify this fraction?

First, we attempt to divide 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 + 3/7

12
13
+
3
7
=
123
91
© 2014 Randy Tayler