math help

What is 25/15 + 1/5?

What is 25/15 + 1/5?

Here's how we add

25
15
+
1
5

Step 1

Our denominators (bottom numbers) don't match, so we can't add yet.

Since 5 is evenly divided by 15, we can multiply just one term to get a common denominator.

Multiply 1 by 3, and get 3, then we multiply 5 by 3 and get 15.

1/5 times 3

The problem now has new fractions to add:

25
15
+
3
15

Step 2

Since our denominators match, we can add the numerators.

25 + 3 = 28

The sum we get is

28
15

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...

No good. 17 is larger than 15. So we're done reducing.

Congratulations! Here's your final answer to 25/15 + 1/5

25
15
+
1
5
=
28
15
© 2014 Randy Tayler