Here's how to subtract 8/12 from 6/9:
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 6 by 12, and get 72.
Then we multiply 8 by 9, and get 72.
Next we give both terms new denominators -- 9 × 12 = 108.
So now our fractions look like this:
Since our denominators match, we can subtract the numerators.
72 − 72 = 0
So the answer is:
|Zero divided by anything is just zero. So that's the final answer:|