Step by step
The question
Question: simplify (x + 2)/x(x − 3) ÷ (x + 2)/(x − 3).
1 Flip and multiply
Dividing by a fraction is the same as times its flip.
Keep the first fraction.
Change divide to times.
Turn the second fraction upside down.
So we work out (x + 2)/x(x − 3) × (x − 3)/(x + 2).
2 Factor every part
First the bottom of the first fraction: x(x − 3).
It is already factored: x(x − 3) means x times (x − 3).
We just read the factors.
So the bottom of the first fraction is x(x − 3).
3 Cross out the same
Careful!
We cross out only a whole bracket, or a whole x, that multiplies everything.
Never one part of a bracket.
Now every part is factored.
A bracket on any top and the same bracket on any bottom make 1.
(x + 2)/(x + 2) is 1.
Cross them out.
(x − 3)/(x − 3) is 1.
Cross them out.
4 Multiply what is left
Top times top, bottom times bottom.
What is left is 1 over x.
One more thing: the bottoms of the question can't be 0.
So x can't be −2, 0 or 3.
5 Check
Let's check with a number: x = 2.
First in the question, flipped.
We get 1/2.
Now in our answer.
We get 1/2 too.
Both are 1/2.
So 1/x is right!
Let's look back.
First: flip and multiply.
Then: factor every part.
Then: cross out the same.
Then: multiply what is left.
Last: check.