math help

What is 72/63 + 3/11?

What is 72/63 + 3/11?

This is how you add

72
63
+
3
11

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now 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 3 by 63, and get 189, then multiply 63 by 11 and get 693.

3/11 times 63

This gives us a new problem that looks like so:

792
693
+
189
693

Step 2

Since our denominators match, we can add the numerators.

792 + 189 = 981

So what's the answer so far?

981
693

Step 3

Can this fraction be reduced?

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:

981
693
÷ 3 =
327
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:

327
231
÷ 3 =
109
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 + 3/11

72
63
+
3
11
=
109
77
© 2014 Randy Tayler