math help

What is 91/6 + 4/9?

What is 91/6 + 4/9?

Here's how you add

91
6
+
4
9

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 91 by 9, and get 819, then we multiply 6 by 9 and get 54.

91/6 times 9

Do the same for the second term. We multiply 4 by 6, and get 24, then multiply 6 by 9 and get 54.

4/9 times 6

The problem now has new fractions to add:

819
54
+
24
54

Step 2

Since our denominators match, we can add the numerators.

819 + 24 = 843

The sum we get is

843
54

Step 3

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

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

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:

843
54
÷ 3 =
281
18

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 18. So we're done reducing.

And we're done! Here's the final answer to 91/6 + 4/9

91
6
+
4
9
=
281
18
© 2014 Randy Tayler