( f + g) (x) =
f(x) + g(x) =
[ x^3 - x ] + [ x^3 + 2x^2 - 10 ] =
2x^3 + 2x^2 - x - 10
( f - g) (x) =
f(x) - g(x) =
[ x^3 - 2x^2 + 12x - 6 ] - [ 4x^2 - 6x + 4 ] =
x^3 - 6x^2 + 18x - 10
( f * g)(x) =
f(x) * g(x) =
[x^2 + 2x - 6 ] * [ x^4 + 3 ] =
x^6 + 2x^5 - 6x^4 + 3x^2 + 6x - 18