math help

What is 3/9 - 6/10?

What is 3/9 - 6/10?

Here's how to subtract 6/10 from 3/9:

3
9
6
10

Step 1

We can't subtract two fractions with different denominators. So you need to get a common denominator. 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 3 by 10, and get 30.

Then we multiply 6 by 9, and get 54.

Next we give both terms new denominators -- 9 × 10 = 90.

So now our fractions look like this:

30
90
54
90

Step 2

Since our denominators match, we can subtract the numerators.

30 − 54 = -24

So the answer is:

-24
90

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:

-24
90
÷ 2 =
-12
45

Let's try dividing by 2 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:

-12
45
÷ 3 =
-4
15

Let's try dividing by 3 again...

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

No good. 5 is larger than -4. So we're done reducing.

There you have it! The final answer is:
3
9
6
10
=
4
15