Which value makes x−3x2−x−6\dfrac{x-3}{x^2 - x - 6}x2−x−6x−3 undefined?
x=3x = 3x=3 and x=−2x = -2x=−2
x=3x = 3x=3 only
x=−3x = -3x=−3 and x=2x = 2x=2
x=6x = 6x=6 only