math help

What is 4/5 + 1/7?

What is 4/5 + 1/7?

This is how we add

4
5
+
1
7

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 4 by 7, and get 28, then we multiply 5 by 7 and get 35.

4/5 times 7

Now for the second term. You multiply 1 by 5, and get 5, then multiply 5 by 7 and get 35.

1/7 times 5

This gives us a new problem that looks like so:

28
35
+
5
35

Step 2

Since our denominators match, we can add the numerators.

28 + 5 = 33

That gives us an answer of

33
35

Step 3

Can this fraction be reduced?

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

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

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. So next you try the next prime number, which is 23...

No good. So next you try the next prime number, which is 29...

No good. So next you try the next prime number, which is 31...

No good. So next you try the next prime number, which is 37...

No good. 37 is larger than 33. So we're done reducing.

And we're done! Here's the final answer to 4/5 + 1/7

4
5
+
1
7
=
33
35
© 2014 Randy Tayler