85.6. 1) 7x - (x - 2) = 13 – x(x – 6);
3) -16 + (4 + x) = x²(x + 12);​

Объяснение:

1) 7x - (x - 2) = 13 – x(x – 6)

7x - x + 2 = 13 - x^2 + 6x

6x + 2 = 13 - x^2 + 6x

6x - 6x + x^2 = 13 - 2

x^2 = 11

x1 =

x2 =

2)-16 + (4 + x) = x²(x + 12)

-16 + 4 + x = x^3 + 12x

x^3 + 12x - x -4 + 16 = 0

x^3 + 11x + 12 = 0

Дальше не умею