math help

What is 9/34 + 9/12?

What is 9/34 + 9/12?

Let's add

9
34
+
9
12

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 9 by 12, and get 108, then we multiply 34 by 12 and get 408.

9/34 times 12

Do the same for the second term. We multiply 9 by 34, and get 306, then multiply 34 by 12 and get 408.

9/12 times 34

So now our fractions look like this:

108
408
+
306
408

Step 2

Since our denominators match, we can add the numerators.

108 + 306 = 414

So the answer is:

414
408

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...

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

414
408
÷ 2 =
207
204

Now, try the same number again.

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

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

207
204
÷ 3 =
69
68

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...

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...

No good. 71 is larger than 69. So we're done reducing.

Congratulations! Here's your final answer to 9/34 + 9/12

9
34
+
9
12
=
69
68
© 2014 Randy Tayler