math help

What is 30/50 + 7/11?

What is 30/50 + 7/11?

Here's how to add

30
50
+
7
11

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 30 by 11, and get 330, then we multiply 50 by 11 and get 550.

30/50 times 11

Do the same for the second term. We multiply 7 by 50, and get 350, then multiply 50 by 11 and get 550.

7/11 times 50

The problem now has new fractions to add:

330
550
+
350
550

Step 2

Since our denominators match, we can add the numerators.

330 + 350 = 680

This yields the answer

680
550

Step 3

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

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:

680
550
÷ 2 =
340
275

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...

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

340
275
÷ 5 =
68
55

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 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. So next you try the next prime number, which is 41...

No good. So next you try the next prime number, which is 43...

No good. So next you try the next prime number, which is 47...

No good. So next you try the next prime number, which is 53...

No good. So next you try the next prime number, which is 59...

No good. 59 is larger than 55. So we're done reducing.

And we're done! Here's the final answer to 30/50 + 7/11

30
50
+
7
11
=
68
55
© 2014 Randy Tayler