math help

What is 25/9 + 8/12?

What is 25/9 + 8/12?

Here's how you add

25
9
+
8
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 25 by 12, and get 300, then we multiply 9 by 12 and get 108.

25/9 times 12

Do the same for the second term. We multiply 8 by 9, and get 72, then multiply 9 by 12 and get 108.

8/12 times 9

The problem now has new fractions to add:

300
108
+
72
108

Step 2

Since our denominators match, we can add the numerators.

300 + 72 = 372

The sum we get is

372
108

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:

372
108
÷ 2 =
186
54

Let's try dividing by that again...

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

186
54
÷ 2 =
93
27

Let's try dividing by that again...

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

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

93
27
÷ 3 =
31
9

Let's try dividing by that again...

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...

No good. 11 is larger than 9. So we're done reducing.

There you have it! Here's the final answer to 25/9 + 8/12

25
9
+
8
12
=
31
9
© 2014 Randy Tayler