а) (2x + y)^2 - (2x - y)^2 = 4x^2 + 4xy + y^2 - (4x^2 - 4xy + y^2) = 8xб) (c - (a + b))^2 = (c - a - b)^2 = c^2 - 2ca - 2cb + a^2 + 2ab + b^2
а) (2x + y)^2 - (2x - y)^2 = 4x^2 + 4xy + y^2 - (4x^2 - 4xy + y^2) = 8x
б) (c - (a + b))^2 = (c - a - b)^2 = c^2 - 2ca - 2cb + a^2 + 2ab + b^2