math help

What is 57/7 + 2/12?

What is 57/7 + 2/12?

Let's add

57
7
+
2
12

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 57 by 12, and get 684, then we multiply 7 by 12 and get 84.

57/7 times 12

Do the same for the second term. We multiply 2 by 7, and get 14, then multiply 7 by 12 and get 84.

2/12 times 7

The problem now has new fractions to add:

684
84
+
14
84

Step 2

Since our denominators match, we can add the numerators.

684 + 14 = 698

The sum we get is

698
84

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:

698
84
÷ 2 =
349
42

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 3...

Nope! So now we try the next greatest prime number, 5...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

Nope! So now we try the next greatest prime number, 41...

Nope! So now we try the next greatest prime number, 43...

No good. 43 is larger than 42. So we're done reducing.

There you have it! Here's the final answer to 57/7 + 2/12

57
7
+
2
12
=
349
42
© 2014 Randy Tayler