math help

What is 25/15 + 2/5?

What is 25/15 + 2/5?

Here's how you add

25
15
+
2
5

Step 1

We have to make sure the denominators are equal.

15 goes into 5 evenly, so we only need to multiply one term to get a common denominator.

Multiply 2 by 3, and get 6, then we multiply 5 by 3 and get 15.

2/5 times 3

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

25
15
+
6
15

Step 2

Since our denominators match, we can add the numerators.

25 + 6 = 31

That gives us the sum, which is

31
15

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. 17 is larger than 15. So we're done reducing.

And we're done! Here's the final answer to 25/15 + 2/5

25
15
+
2
5
=
31
15
© 2014 Randy Tayler