math help

What is 72/63 + 6/10?

What is 72/63 + 6/10?

Here's how we add

72
63
+
6
10

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 10, and get 720, then we multiply 63 by 10 and get 630.

72/63 times 10

Now for the second term. You multiply 6 by 63, and get 378, then multiply 63 by 10 and get 630.

6/10 times 63

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

720
630
+
378
630

Step 2

Since our denominators match, we can add the numerators.

720 + 378 = 1098

That gives us the sum, which is

1098
630

Step 3

Now, do we need to simplify this fraction?

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

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

1098
630
÷ 2 =
549
315

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:

549
315
÷ 3 =
183
105

Now, try the same number again.

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

183
105
÷ 3 =
61
35

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...

No good. 37 is larger than 35. So we're done reducing.

Congratulations! Here's your final answer to 72/63 + 6/10

72
63
+
6
10
=
61
35
© 2014 Randy Tayler