math help

What is 20/17 + 5/10?

What is 20/17 + 5/10?

This is how we add

20
17
+
5
10

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 10, and get 200, then we multiply 17 by 10 and get 170.

20/17 times 10

Do the same for the second term. We multiply 5 by 17, and get 85, then multiply 17 by 10 and get 170.

5/10 times 17

So now our fractions look like this:

200
170
+
85
170

Step 2

Since our denominators match, we can add the numerators.

200 + 85 = 285

Now we have an answer.

285
170

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...

Nope. Try the next prime number, 5...

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

285
170
÷ 5 =
57
34

Now, try the same number again.

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 + 5/10

20
17
+
5
10
=
57
34
© 2014 Randy Tayler