math help

What is 15/11 + 1/7?

What is 15/11 + 1/7?

This is how to add

15
11
+
1
7

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 7, and get 105, then we multiply 11 by 7 and get 77.

15/11 times 7

Do the same for the second term. We multiply 1 by 11, and get 11, then multiply 11 by 7 and get 77.

1/7 times 11

The problem now has new fractions to add:

105
77
+
11
77

Step 2

Since our denominators match, we can add the numerators.

105 + 11 = 116

This yields the answer

116
77

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...

Nope. Try the next prime number, 61...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

Nope. Try the next prime number, 73...

Nope. Try the next prime number, 79...

No good. 79 is larger than 77. So we're done reducing.

Congratulations! Here's your final answer to 15/11 + 1/7

15
11
+
1
7
=
116
77
© 2014 Randy Tayler