Откроем скобки:
d(3 + 2d - d^2) - d^2(3 - d) + d(d - 5) = 3d + 2d^2 - d^3 - 3d^2 + d^3 + d^2 - 5d = 3d - 5d = -2d.
Откроем скобки:
d(3 + 2d - d^2) - d^2(3 - d) + d(d - 5) = 3d + 2d^2 - d^3 - 3d^2 + d^3 + d^2 - 5d = 3d - 5d = -2d.