x^2 - 5x - 6 = 0, x^2 + 5x - 6 = 0, -x^2 + 5x - 6 = 0, x^2 + 5x + 6 = 0, x^2 - 5x = 6 = 0, x^2 - 5x + 6 = 0, X^2+5x-6=0, x^2 -5x + 6 ≤ 0, -x^2+5x-6=0, x^2 + 5x − 6 = 0, x^2+5x+6=0