math help

What is 45/3 + 2/5?

What is 45/3 + 2/5?

This is how to add

45
3
+
2
5

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 45 by 5, and get 225, then we multiply 3 by 5 and get 15.

45/3 times 5

Now for the second term. You multiply 2 by 3, and get 6, then multiply 3 by 5 and get 15.

2/5 times 3

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

225
15
+
6
15

Step 2

Since our denominators match, we can add the numerators.

225 + 6 = 231

That gives us the sum, which is

231
15

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:

231
15
÷ 3 =
77
5

Now, try the same number again.

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

Nope. Try the next prime number, 7...

No good. 7 is larger than 5. So we're done reducing.

Congratulations! Here's your final answer to 45/3 + 2/5

45
3
+
2
5
=
77
5
© 2014 Randy Tayler