math help

What is 15/11 + 3/5?

What is 15/11 + 3/5?

This is how to add

15
11
+
3
5

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 15 by 5, and get 75, then we multiply 11 by 5 and get 55.

15/11 times 5

Do the same for the second term. We multiply 3 by 11, and get 33, then multiply 11 by 5 and get 55.

3/5 times 11

The problem now has new fractions to add:

75
55
+
33
55

Step 2

Since our denominators match, we can add the numerators.

75 + 33 = 108

This yields the answer

108
55

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...

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...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

Nope. Try the next prime number, 53...

Nope. Try the next prime number, 59...

No good. 59 is larger than 55. So we're done reducing.

Congratulations! Here's your final answer to 15/11 + 3/5

15
11
+
3
5
=
108
55
© 2014 Randy Tayler