math help

What is 72/63 + 9/11?

What is 72/63 + 9/11?

Let's add

72
63
+
9
11

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 72 by 11, and get 792, then we multiply 63 by 11 and get 693.

72/63 times 11

Now for the second term. You multiply 9 by 63, and get 567, then multiply 63 by 11 and get 693.

9/11 times 63

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

792
693
+
567
693

Step 2

Since our denominators match, we can add the numerators.

792 + 567 = 1359

Answer:

1359
693

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:

1359
693
÷ 3 =
453
231

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:

453
231
÷ 3 =
151
77

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. So next you try the next prime number, which is 7...

No good. So next you try the next prime number, which is 11...

No good. So next you try the next prime number, which is 13...

No good. So next you try the next prime number, which is 17...

No good. So next you try the next prime number, which is 19...

No good. So next you try the next prime number, which is 23...

No good. So next you try the next prime number, which is 29...

No good. So next you try the next prime number, which is 31...

No good. So next you try the next prime number, which is 37...

No good. So next you try the next prime number, which is 41...

No good. So next you try the next prime number, which is 43...

No good. So next you try the next prime number, which is 47...

No good. So next you try the next prime number, which is 53...

No good. So next you try the next prime number, which is 59...

No good. So next you try the next prime number, which is 61...

No good. So next you try the next prime number, which is 67...

No good. So next you try the next prime number, which is 71...

No good. So next you try the next prime number, which is 73...

No good. So next you try the next prime number, which is 79...

No good. 79 is larger than 77. So we're done reducing.

And we're done! Here's the final answer to 72/63 + 9/11

72
63
+
9
11
=
151
77
© 2014 Randy Tayler