math help

What is 2/6 - 7/9?

What is 2/6 - 7/9?

Here's how to subtract 7/9 from 2/6:

2
6
7
9

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 2 by 9, and get 18.

Then we multiply 7 by 6, and get 42.

Next we give both terms new denominators -- 6 × 9 = 54.

So now our fractions look like this:

18
54
42
54

Step 2

Since our denominators match, we can subtract the numerators.

18 − 42 = -24

So the answer is:

-24
54

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
54
÷ 2 =
-12
27

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
27
÷ 3 =
-4
9

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:
2
6
7
9
=
4
9