math help

What is 72/63 + 3/4?

What is 72/63 + 3/4?

This is how you add

72
63
+
3
4

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 72 by 4, and get 288, then we multiply 63 by 4 and get 252.

72/63 times 4

Do the same for the second term. We multiply 3 by 63, and get 189, then multiply 63 by 4 and get 252.

3/4 times 63

The problem now has new fractions to add:

288
252
+
189
252

Step 2

Since our denominators match, we can add the numerators.

288 + 189 = 477

The sum we get is

477
252

Step 3

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

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

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

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

477
252
÷ 3 =
159
84

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

159
84
÷ 3 =
53
28

Now, try the same number again.

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...

No good. 29 is larger than 28. So we're done reducing.

Congratulations! Here's your final answer to 72/63 + 3/4

72
63
+
3
4
=
53
28
© 2014 Randy Tayler