Mathematics > Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer.

If, for which of the following values of x is y NOT defined?

(A) -4

(B) -3

(C) -1

(D) 2

(E) 3 

正确答案>>>

The correct answer is B

Explanation

Division by 0 is not defined, so  is not defined when (x +3) (x -4) =0. The product (x +3) (x -4) is equal to 0，if x =-3 or if x =4. Therefore, y is defined for all of the choices except - 3.