a) A + B = (4x - 3) + (-2x + 3y) = 4x - 3 + (-2x) + 3y = 2x + 3y - 3
b) B - A = (-2x + 3y) - (4x - 3) = (-2x) + 3y - 4x + 3 = (-6x) + 3y + 3, możemy wynieść (-3) przed nawias i wtedy otrzymamy: -3( 2x - y - 1)
c) -A - B = -(4x - 3) - ( -2x + 3y) = -4x + 3 + 2x - 3y = -2x - 3y + 3