P(x) = x^2 - 2^3 + x; Q(x) = x^3 - 2^2 +1; R(x) = x^3 + 2 - x^2. Tính: P(x) + Q(x) + R(x)

Cho:
P(x) = x^2 - 2^3 + x
Q(x) = x^3 - 2^2 +1
R(x) = x^3 + 2 - x^2
Tính:
a, P(x) + Q(x) + R(x)
b, P(x) - Q(x) - R(x)
c, P(x) + Q(x) - R(x)
d, P(x) - Q(x) + R(x)
e, Q(x) - P(x) - R(x)