math help

What is 30/50 + 8/9?

What is 30/50 + 8/9?

This is how to add

30
50
+
8
9

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 30 by 9, and get 270, then we multiply 50 by 9 and get 450.

30/50 times 9

Now for the second term. You multiply 8 by 50, and get 400, then multiply 50 by 9 and get 450.

8/9 times 50

This gives us a new problem that looks like so:

270
450
+
400
450

Step 2

Since our denominators match, we can add the numerators.

270 + 400 = 670

That gives us an answer of

670
450

Step 3

Can this fraction be reduced?

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

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

670
450
÷ 2 =
335
225

Now, try the same number again.

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

Nope. Try the next prime number, 5...

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

335
225
÷ 5 =
67
45

Now, try the same number again.

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...

No good. 47 is larger than 45. So we're done reducing.

Congratulations! Here's your final answer to 30/50 + 8/9

30
50
+
8
9
=
67
45
© 2014 Randy Tayler