The lengths of two sides of a triangle are shown below: side 1: 3x2 − 4x − 1 side 2: 4x − x2 + 5 the perimeter of the triangle is 5x3 − 2x2 + 3x − 8. 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)

A: total length of 2 sides (i.e. side 1 & 2) = side 1 + side 2= (3x^2 - 4x - 1) + (4x - x^2 + 5)= (3x^2 - x^2) + (4x - 4x) + (5 - 1)= 2x^2 + 0 + 4=2x^2 + 4b: perimeter of triangle = side 1 + side 2 + side 35x^3 - 2x^2 + 3x - 8 = (2x^2 + 4) + side 3{subtract both sides of equation by (2x^2 + 4)}5x^3 - 2x^2 - 2x^2 + 3x - 8 - 4 = side 35x^3 - 4x^2 + 3x - 12 = side 3hence, side 3 = 5x^3 - 4x^2 + 3x - 12c: not very sure about what the question requirement is..hope this !

Where is the expression you want us to evaluate?