Which of the following is a quadratic function?

A. y = (x + 2) (2x - 3)

B. y = 3 (x-4)

mo a

D. y = x (x-4) (x+3)

A is the answer, because the highest exponent is 2.

quadratic

A's expression foiled would be 2x^2 + x - 6

B's expression foiled would be 3x - 12, where the exponent on x is only 1.

D's expression foiled would be x^3 - x^2 - 12x, where the exponent on x is 3.