 # What is 2/5 + 3/7? 2 5
+
 3 7

## 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 2 by 7, and get 14, then we multiply 5 by 7 and get 35. Now for the second term. You multiply 3 by 5, and get 15, then multiply 5 by 7 and get 35. This gives us a new problem that looks like so:

 14 35
+
 15 35

## Step 2

Since our denominators match, we can add the numerators.

14 + 15 = 29

That gives us an answer of

 29 35

## Step 3

Can this fraction be reduced?

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. 31 is larger than 29. So we're done reducing.

And we're done! Here's the final answer to 2/5 + 3/7

 2 5
+
 3 7
=
 29 35