math help

What is 20/17 + 6/9?

What is 20/17 + 6/9?

This is how we add

20
17
+
6
9

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 20 by 9, and get 180, then we multiply 17 by 9 and get 153.

20/17 times 9

Do the same for the second term. We multiply 6 by 17, and get 102, then multiply 17 by 9 and get 153.

6/9 times 17

So now our fractions look like this:

180
153
+
102
153

Step 2

Since our denominators match, we can add the numerators.

180 + 102 = 282

Now we have an answer.

282
153

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

To find out, we try dividing it by 2...

Nope. Try the next prime number, 3...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

282
153
÷ 3 =
94
51

Now, try the same number again.

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...

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

Congratulations! Here's your final answer to 20/17 + 6/9

20
17
+
6
9
=
94
51
© 2014 Randy Tayler