math help

What is 45/4 + 5/12?

What is 45/4 + 5/12?

This is how we add

45
4
+
5
12

Step 1

Now we need to make our denominators match.

Since 4 is evenly divided by 12, we can multiply just one term to get a common denominator.

Multiply 45 by 3, and get 135, then we multiply 4 by 3 and get 12.

45/4 times 3

The problem now has new fractions to add:

135
12
+
5
12

Step 2

Since our denominators match, we can add the numerators.

135 + 5 = 140

This yields the answer

140
12

Step 3

The last step is to reduce the fraction if we can.

To find out, we try dividing it by 2...

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

140
12
÷ 2 =
70
6

Let's try dividing by that again...

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

70
6
÷ 2 =
35
3

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 3...

Nope! So now we try the next greatest prime number, 5...

No good. 5 is larger than 3. So we're done reducing.

There you have it! Here's the final answer to 45/4 + 5/12

45
4
+
5
12
=
35
3
© 2014 Randy Tayler