а) -3x(2-x) + (3x+1)(x-2) = -6x + 3x^2 + 3x - 6 + x - 2 = 3x^2 - 2
б) 3(2x-1)^2 + 12x = 3(4x^2 - 4x + 1) + 12x = 12x^2 - 12x + 3 + 12x = 12x^2 + 3
в) (x+3)^2 - (x-2)(x+2) = x^2 + 6x + 9 - (x^2 - 2x + 2x - 4) = x^2 + 6x + 9 - x^2 + 4 = 6x + 13
а) -3x(2-x) + (3x+1)(x-2) = -6x + 3x^2 + 3x - 6 + x - 2 = 3x^2 - 2
б) 3(2x-1)^2 + 12x = 3(4x^2 - 4x + 1) + 12x = 12x^2 - 12x + 3 + 12x = 12x^2 + 3
в) (x+3)^2 - (x-2)(x+2) = x^2 + 6x + 9 - (x^2 - 2x + 2x - 4) = x^2 + 6x + 9 - x^2 + 4 = 6x + 13