math help

What is 25/15 + 4/11?

What is 25/15 + 4/11?

This is how to add

25
15
+
4
11

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 25 by 11, and get 275, then we multiply 15 by 11 and get 165.

25/15 times 11

Now for the second term. You multiply 4 by 15, and get 60, then multiply 15 by 11 and get 165.

4/11 times 15

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

275
165
+
60
165

Step 2

Since our denominators match, we can add the numerators.

275 + 60 = 335

That gives us the sum, which is

335
165

Step 3

Now, do we need to simplify this fraction?

First, we attempt to divide it by 2...

Nope. Try the next prime number, 3...

Nope. Try the next prime number, 5...

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

335
165
÷ 5 =
67
33

Now, try the same number again.

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...

No good. 37 is larger than 33. So we're done reducing.

Congratulations! Here's your final answer to 25/15 + 4/11

25
15
+
4
11
=
67
33
© 2014 Randy Tayler