math help

What is 7/20 + 8/11?

What is 7/20 + 8/11?

Here's how we add

7
20
+
8
11

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 7 by 11, and get 77, then we multiply 20 by 11 and get 220.

7/20 times 11

Do the same for the second term. We multiply 8 by 20, and get 160, then multiply 20 by 11 and get 220.

8/11 times 20

The problem now has new fractions to add:

77
220
+
160
220

Step 2

Since our denominators match, we can add the numerators.

77 + 160 = 237

The sum we get is

237
220

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...

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...

Nope. Try the next prime number, 103...

Nope. Try the next prime number, 107...

Nope. Try the next prime number, 109...

Nope. Try the next prime number, 113...

Nope. Try the next prime number, 127...

Nope. Try the next prime number, 131...

Nope. Try the next prime number, 137...

Nope. Try the next prime number, 139...

Nope. Try the next prime number, 149...

Nope. Try the next prime number, 151...

Nope. Try the next prime number, 157...

Nope. Try the next prime number, 163...

Nope. Try the next prime number, 167...

Nope. Try the next prime number, 173...

Nope. Try the next prime number, 179...

Nope. Try the next prime number, 181...

Nope. Try the next prime number, 191...

Nope. Try the next prime number, 193...

Nope. Try the next prime number, 197...

Nope. Try the next prime number, 199...

Nope. Try the next prime number, 211...

Nope. Try the next prime number, 223...

No good. 223 is larger than 220. So we're done reducing.

Congratulations! Here's your final answer to 7/20 + 8/11

7
20
+
8
11
=
237
220
© 2014 Randy Tayler