Multiplying and dividing rational expressions
The question
x/(x − 7) × (x − 7)/(x − 4)
x/(x − 7) ×
x/(x − 7) ×
(x − 7) cancels
x / (x − 4)
x ≠ 4, 7
- Now it is one product, so anything on top may cancel with anything underneath. (x − 7) appears in both, so it goes.
- What is left is x / (x − 4).
- One more thing: x may not be 4 or 7. Those made a denominator zero in the original question — even the (x − 7) that canceled.
How it works.
- 01
Now it is one product, so anything on top may cancel with anything underneath. (x − 7) appears in both, so it goes.
- 02
What is left is x / (x − 4).
- 03
One more thing: x may not be 4 or 7. Those made a denominator zero in the original question — even the (x − 7) that canceled.