When we divide algebraic fractions, we use the same method as when we divide numerical fractions.
Remember the KFC rule: Keep the first fraction, flip the second fraction and change the sign.
First, we invert the second fraction and then turn the ÷ sign into a x sign.
Then we try to reduce or cancel down any top term with a bottom term that has a common factor.
Example
Simplify:
a3 | ÷ | 7a2 |
10 | 5 |
Answer
Invert the second fraction and change the ÷ sign to a x sign.
a3 | x | 5 |
10 | 7a2 |
Now multiply the numerators to get 5a3
And multiply the denominators to get 70a2
This gives us:
5a3 |
70a2 |
Now we simplify this by dividing the numbers by a common factor.
5 is a common factor of 5 and 70, so divide them both by 5. This gives us 1 as the numerator and 14 as the denominator.
Remember the rule for dividing by powers? a3 ÷ a2 = a3-2 = a
We end up with
a |
14 |
Let's try some questions.