- x = 5х -36
-x^2 = 5x - 36 -x^2 - 5x + 36 = 0 x^2 + 5x - 36 = 0 x = -5±√5^2-4•1•(-36) / 2•1 x = -5±√25 + 144 / 2 x = -5±√169 / 2 x = -5±13 /2 x1 = -9 x2 = 4