math help

What is 72/63 + 5/11?

What is 72/63 + 5/11?

Here's how we add

72
63
+
5
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 5 by 63, and get 315, then multiply 63 by 11 and get 693.

5/11 times 63

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

792
693
+
315
693

Step 2

Since our denominators match, we can add the numerators.

792 + 315 = 1107

That gives us the sum, which is

1107
693

Step 3

Now, do we need to simplify this fraction?

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

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

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

1107
693
÷ 3 =
369
231

Now, try the same number again.

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

369
231
÷ 3 =
123
77

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...

Nope. Try the next prime number, 73...

Nope. Try the next prime number, 79...

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

Congratulations! Here's your final answer to 72/63 + 5/11

72
63
+
5
11
=
123
77
© 2014 Randy Tayler