math help

What is 20/17 + 8/12?

What is 20/17 + 8/12?

Let's add

20
17
+
8
12

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 12, and get 240, then we multiply 17 by 12 and get 204.

20/17 times 12

Now for the second term. You multiply 8 by 17, and get 136, then multiply 17 by 12 and get 204.

8/12 times 17

This gives us a new problem that looks like so:

240
204
+
136
204

Step 2

Since our denominators match, we can add the numerators.

240 + 136 = 376

That gives us an answer of

376
204

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:

376
204
÷ 2 =
188
102

Let's try dividing by that again...

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

188
102
÷ 2 =
94
51

Let's try dividing by that again...

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...

No good. 53 is larger than 51. So we're done reducing.

There you have it! Here's the final answer to 20/17 + 8/12

20
17
+
8
12
=
94
51
© 2014 Randy Tayler