a) (5x-4y)+(5x+4y) = 5x - 4y + 5x + 4y = 10x
б) (2+3x-4x^2)+(4x^2-3x+2) = -4x^2 + 4x^2 + 3x - 3x + 2 + 2 = 4
a) (5x-4y)+(5x+4y) = 5x - 4y + 5x + 4y = 10x
б) (2+3x-4x^2)+(4x^2-3x+2) = -4x^2 + 4x^2 + 3x - 3x + 2 + 2 = 4