math help

What is 15/11 + 6/7?

What is 15/11 + 6/7?

Here's how we add

15
11
+
6
7

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

15/11 times 7

Now for the second term. You multiply 6 by 11, and get 66, then multiply 11 by 7 and get 77.

6/7 times 11

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

105
77
+
66
77

Step 2

Since our denominators match, we can add the numerators.

105 + 66 = 171

That gives us the sum, which is

171
77

Step 3

Now, do we need to simplify this fraction?

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

Nope! So now we try the next greatest prime number, 3...

Nope! So now we try the next greatest prime number, 5...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

Nope! So now we try the next greatest prime number, 41...

Nope! So now we try the next greatest prime number, 43...

Nope! So now we try the next greatest prime number, 47...

Nope! So now we try the next greatest prime number, 53...

Nope! So now we try the next greatest prime number, 59...

Nope! So now we try the next greatest prime number, 61...

Nope! So now we try the next greatest prime number, 67...

Nope! So now we try the next greatest prime number, 71...

Nope! So now we try the next greatest prime number, 73...

Nope! So now we try the next greatest prime number, 79...

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

There you have it! Here's the final answer to 15/11 + 6/7

15
11
+
6
7
=
171
77
© 2014 Randy Tayler