Simplify the rational expression.

(45y-9xy)/(x^2y-25y)

I got an answer of 9y/y(x+5) but it seems to be wrong. Can anyone solve this for me and see what they get? Thank you

9 answers

First take out obvious common factors
(45y-9xy)/(x^2y-25y)
=9y(5-9x)/y(x²-25)

cancel out the common factor y from the numerator and denominator and see if there are other factoring you can do.
I did that u get 9y(5-9x)/((x-5)(x+5)) but it is still wrong
Did you leave the "y" in the numerator?
sorry what I was suppose to write was 9y(5-9x)/y((x-5)(x+5))

do you see where there is still a mistake?
If you have a "y" both in the numerator and denominator, you can cancel them out as long as y≠0.

For example:
5y(x-1)/(25xy²)
=5y(x-1)/(5y(5xy)) ... here, remove 5y, a common factor
=(x-1)/(5xy)
so will the final answer be 9(5-9x)/((x-5)(x+5)) ?
Correct!
It still shows me as wrong when I submit online
Sorry, there was a mistake in:
(45y-9xy)/(x^2y-25y)
=9y(5-9x)/y(x²-25)

Should have read:
(45y-9xy)/(x^2y-25y)
=9y(5-x)/y(x²-25)

Now can you figure out the answer and try again?