math help

What is 25/9 + 2/8?

What is 25/9 + 2/8?

This is how you add

25
9
+
2
8

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 25 by 8, and get 200, then we multiply 9 by 8 and get 72.

25/9 times 8

Do the same for the second term. We multiply 2 by 9, and get 18, then multiply 9 by 8 and get 72.

2/8 times 9

So now our fractions look like this:

200
72
+
18
72

Step 2

Since our denominators match, we can add the numerators.

200 + 18 = 218

Now we have an answer.

218
72

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

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:

218
72
÷ 2 =
109
36

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...

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 36. So we're done reducing.

And we're done! Here's the final answer to 25/9 + 2/8

25
9
+
2
8
=
109
36
© 2014 Randy Tayler