-10x^2+5x+589=(x-1)^2
-10x^2+5x+589= x^2 - 2x + 1
-10x^2 - x^2 + 5x + 2x + 589 - 1 = 0
-11x^2 + 7x + 588 = 0 | : (-1)
11x^2 - 7x - 588 = 0
11x^2/11 - 7x - 588*11 = 0
x -> a
a^2 - 7a - 6468 = 0
a1 = 84
a2 = -77
x1 = 84/11
x2 = -77/11 = -7
Ответ : 84/11; -7