4x² - 5x - 6 =4x² + 3x - 8x - 6 = x(4x - 3) - 2(4x - 3) = (x-2) (4x+3)2x² + 7x + 6 = 2x² + 3x + 4x + 6 = x(2x + 3) + 2(2x + 3) = (2x+3) (x+2)-5x² + 7x + 6 = -5x² - 3x + 1...