math help

What is 11/12 + 3/9?

What is 11/12 + 3/9?

Here's how to add

11
12
+
3
9

Step 1

Can you add yet? Nope! The denominators don't match. We need a common denominator. So next we take both denominators and multiply them. Next, take each numerator and multiply it by the denominator of the other term.

So, we multiply 11 by 9, and get 99, then we multiply 12 by 9 and get 108.

11/12 times 9

Now for the second term. You multiply 3 by 12, and get 36, then multiply 12 by 9 and get 108.

3/9 times 12

We now have a new problem, that looks like this:

99
108
+
36
108

Step 2

Since our denominators match, we can add the numerators.

99 + 36 = 135

Answer:

135
108

Step 3

Now, do we need to simplify this fraction?

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

No good. So next you try the next prime number, which is 3...

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

135
108
÷ 3 =
45
36

So far so good... let's try to divide by that number again.

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

45
36
÷ 3 =
15
12

So far so good... let's try to divide by that number again.

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

15
12
÷ 3 =
5
4

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 5...

No good. 5 is larger than 4. So we're done reducing.

And we're done! Here's the final answer to 11/12 + 3/9

11
12
+
3
9
=
5
4
© 2014 Randy Tayler