math help

What is 78/92 + 2/12?

What is 78/92 + 2/12?

This is how you add

78
92
+
2
12

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 78 by 12, and get 936, then we multiply 92 by 12 and get 1104.

78/92 times 12

Do the same for the second term. We multiply 2 by 92, and get 184, then multiply 92 by 12 and get 1104.

2/12 times 92

So now our fractions look like this:

936
1104
+
184
1104

Step 2

Since our denominators match, we can add the numerators.

936 + 184 = 1120

So the answer is:

1120
1104

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:

1120
1104
÷ 2 =
560
552

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

560
552
÷ 2 =
280
276

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

280
276
÷ 2 =
140
138

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

140
138
÷ 2 =
70
69

Now, try the same number again.

Nope. Try the next prime number, 3...

Nope. Try the next prime number, 5...

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

Nope. Try the next prime number, 53...

Nope. Try the next prime number, 59...

Nope. Try the next prime number, 61...

Nope. Try the next prime number, 67...

Nope. Try the next prime number, 71...

No good. 71 is larger than 70. So we're done reducing.

Congratulations! Here's your final answer to 78/92 + 2/12

78
92
+
2
12
=
70
69
© 2014 Randy Tayler