1)
f(x) + g(x) = 3x^3 + 2x^2 - x - 7 + x^3 - 10x^2 +8
f(x) + g(x) = 4x^3 - 8x^2 - x + 1
2)
f(x) - g(x) =
2) f(x) - g(x) = 3x^3 + 2x^2 - x - 7 - x^3 + 10x^2 - 8- x^3 + 10x^2 - 8
f(x) - g(x) = 2x^3 + 12x^2 - x - 15
3)
(h - f)(x) = -2x^2 +6x - 1 - 3x^3 - 2x^2 + x + 7
(h - f)(x) = - 3x^3 - 4x^2 + 7x + 6
4)
(g + h)(x) = x^3 - 10x^2 +8 -2x^2 + 6x - 1
(g + h)(x) = x^3 - 12x^2 + 6x + 7