x²+6x-16 = x²+8x-2x-16 = x(x+8)-2(x+8) = (x-2)(x+8)
x²-5x-36 = x²+4x-9x-36 = x(x+4)-9(x+4) = (x-9)(x+4)
x²-8x-33 = x²+3x-11x-33 = x(x+3)-11(x+3) = (x-11)(x+3)
x²-9x-52 = x²+4x-13x-52 = x(x+4)-13(x+4) = (x-13)(x+4)
x²-12x+11 = x²-x-11x+11 = x(x-1)-11(x-1) = (x-11)(x-1)