а) (x+y-2)^2 = x^2 + y^2 + 4 + 2xy - 4x - 4yб) (2x+y+z-1)^2 = 4x^2 + y^2 + z^2 + 1 + 4xy + 4xz - 2x - 2y - 2z.
а) (x+y-2)^2 = x^2 + y^2 + 4 + 2xy - 4x - 4y
б) (2x+y+z-1)^2 = 4x^2 + y^2 + z^2 + 1 + 4xy + 4xz - 2x - 2y - 2z.