Can somebody me with this i think i got it not sure though

he lengths of two sides of a triangle are shown below:

side 1: 8x2 − 5x − 2

side 2: 7x − x2 + 3

the perimeter of the triangle is 4x3 − 3x2 + 2x − 6.

part a: what is the total length of the two sides, 1 and 2, of the triangle? (4 points)

part b: what is the length of the third side of the triangle? (4 points)

part c: do the answers for part a and part b show that the polynomials are closed under addition and subtraction? justify your answer. (2 points)

side one = 8x^2-5x-2
side two = 7x-x^2+3
4x^3-3x^2+2-6