math help

What is 10/11 + 7/9?

What is 10/11 + 7/9?

This is how you add

10
11
+
7
9

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 10 by 9, and get 90, then we multiply 11 by 9 and get 99.

10/11 times 9

Now for the second term. You multiply 7 by 11, and get 77, then multiply 11 by 9 and get 99.

7/9 times 11

This gives us a new problem that looks like so:

90
99
+
77
99

Step 2

Since our denominators match, we can add the numerators.

90 + 77 = 167

So what's the answer so far?

167
99

Step 3

Can this fraction be reduced?

First, we attempt to divide 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...

Nope. Try the next prime number, 83...

Nope. Try the next prime number, 89...

Nope. Try the next prime number, 97...

Nope. Try the next prime number, 101...

No good. 101 is larger than 99. So we're done reducing.

Congratulations! Here's your final answer to 10/11 + 7/9

10
11
+
7
9
=
167
99
© 2014 Randy Tayler