a) P(x) = 5x^3 -3x+7x
P(x) = 5x^3 + 4x
Q(x) = -5x^3 + 2x -3+2x -x^2 - 2
Q(x) = -5x^3 + 4x - x^2 -5
b) P(x) = 5x^3 + 4x
+ Q(x) = -5x^3 - x^2 +4x -5
-------------------------------------
M(x) = -x^2 + 8x -5
P(x) = 5x^3 + 4x
- Q(x) = -5x^3 - x^2 +4x -5
-------------------------------------
N(x) = 10x^3 + x^2 +5