Question

Which of the following is equal to the rational expression when x=-3?x²-9X + 3O A.X-3X + 3OB. X+31O c.X-3O D. x-3

Answer 1

We are to get the equivalent expression to the function when x is not equal to - 3.

`(x^2-9)/(x+3)`

First, we try to factorize the numerator, we can see that it is a difference of two squares, so we can factorize it;

`\begin{gathered} (x^2-9)/(x+3)=((x-3)(x+3))/(x+3) \\ \text{the x+3's cancel out to give} \\ (x-3) \end{gathered}`

Therefore, the correct answer is option D.