math help

What is 57/7 + 6/9?

What is 57/7 + 6/9?

This is how you add

57
7
+
6
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 57 by 9, and get 513, then we multiply 7 by 9 and get 63.

57/7 times 9

Now for the second term. You multiply 6 by 7, and get 42, then multiply 7 by 9 and get 63.

6/9 times 7

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

513
63
+
42
63

Step 2

Since our denominators match, we can add the numerators.

513 + 42 = 555

That gives us the sum, which is

555
63

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:

555
63
÷ 3 =
185
21

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...

No good. 23 is larger than 21. So we're done reducing.

Congratulations! Here's your final answer to 57/7 + 6/9

57
7
+
6
9
=
185
21
© 2014 Randy Tayler