math help

What is 100/50 + 7/12?

What is 100/50 + 7/12?

Let's add

100
50
+
7
12

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 100 by 12, and get 1200, then we multiply 50 by 12 and get 600.

100/50 times 12

Now for the second term. You multiply 7 by 50, and get 350, then multiply 50 by 12 and get 600.

7/12 times 50

This gives us a new problem that looks like so:

1200
600
+
350
600

Step 2

Since our denominators match, we can add the numerators.

1200 + 350 = 1550

That gives us an answer of

1550
600

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:

1550
600
÷ 2 =
775
300

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:

775
300
÷ 5 =
155
60

Now, try the same number again.

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

155
60
÷ 5 =
31
12

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...

No good. 13 is larger than 12. So we're done reducing.

Congratulations! Here's your final answer to 100/50 + 7/12

100
50
+
7
12
=
31
12
© 2014 Randy Tayler