posted by Sarah .
simplify. what are the excluded values?
There is a good chance you have missed out parentheses in the numerator and the denominator.
All fractions have implicit (i.e. understood) parentheses in the numerator and denominator.
I believe your question means
(x²+6x+9)/(5x+15) even though the question does not actually show the brackets. When you reduce the expression to a single line, the parentheses are required.
=(x+3)/5 on condition that x≠3