math help

What is 70/51 + 4/12?

What is 70/51 + 4/12?

Here's how we add

70
51
+
4
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 70 by 12, and get 840, then we multiply 51 by 12 and get 612.

70/51 times 12

Now for the second term. You multiply 4 by 51, and get 204, then multiply 51 by 12 and get 612.

4/12 times 51

This gives us a new problem that looks like so:

840
612
+
204
612

Step 2

Since our denominators match, we can add the numerators.

840 + 204 = 1044

That gives us an answer of

1044
612

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:

1044
612
÷ 2 =
522
306

So far so good... let's try to divide by that number again.

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

522
306
÷ 2 =
261
153

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

261
153
÷ 3 =
87
51

So far so good... let's try to divide by that number again.

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

87
51
÷ 3 =
29
17

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 5...

No good. So next you try the next prime number, which is 7...

No good. So next you try the next prime number, which is 11...

No good. So next you try the next prime number, which is 13...

No good. So next you try the next prime number, which is 17...

No good. So next you try the next prime number, which is 19...

No good. 19 is larger than 17. So we're done reducing.

And we're done! Here's the final answer to 70/51 + 4/12

70
51
+
4
12
=
29
17
© 2014 Randy Tayler