math help

What is 25/15 + 8/10?

What is 25/15 + 8/10?

This is how you add

25
15
+
8
10

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 10, and get 250, then we multiply 15 by 10 and get 150.

25/15 times 10

Do the same for the second term. We multiply 8 by 15, and get 120, then multiply 15 by 10 and get 150.

8/10 times 15

The problem now has new fractions to add:

250
150
+
120
150

Step 2

Since our denominators match, we can add the numerators.

250 + 120 = 370

This yields the answer

370
150

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:

370
150
÷ 2 =
185
75

Now, try the same number again.

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

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

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

185
75
÷ 5 =
37
15

Now, try the same number again.

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...

No good. 17 is larger than 15. So we're done reducing.

Congratulations! Here's your final answer to 25/15 + 8/10

25
15
+
8
10
=
37
15
© 2014 Randy Tayler