math help

What is 20/17 + 4/8?

What is 20/17 + 4/8?

Here's how to add

20
17
+
4
8

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 20 by 8, and get 160, then we multiply 17 by 8 and get 136.

20/17 times 8

Now for the second term. You multiply 4 by 17, and get 68, then multiply 17 by 8 and get 136.

4/8 times 17

This gives us a new problem that looks like so:

160
136
+
68
136

Step 2

Since our denominators match, we can add the numerators.

160 + 68 = 228

That gives us an answer of

228
136

Step 3

Can this fraction be reduced?

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

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

228
136
÷ 2 =
114
68

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

114
68
÷ 2 =
57
34

Now, try the same number again.

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...

No good. 37 is larger than 34. So we're done reducing.

Congratulations! Here's your final answer to 20/17 + 4/8

20
17
+
4
8
=
57
34
© 2014 Randy Tayler