SERIOUSE HELP PLEASE!!!!!!!!!
side 1 : 3x^2-4x-1
side 2 : 4x-x^2+5
the perimeter if the triangle is 5x^3-2x^2+3x-8

Part A: What is the total length of the two slides, 1 and 2, of the triangle?
Part B: What is the length of the third side of the triangle?
Part C: Do the answers for Part A and B show that the polynomials are closed under addition and subtraction? justify your answer.

Question

SERIOUSE HELP PLEASE!!!!!!!!!
side 1 : 3x^2-4x-1
side 2 : 4x-x^2+5 
the perimeter if the triangle  is 5x^3-2x^2+3x-8

Part A: What is the total length of the two slides, 1 and 2, of the triangle?
Part B: What is the length of the third side of the triangle? 
Part C: Do the answers for Part A and B show that the polynomials are closed under addition and subtraction? justify your answer.

mathmale · Answer

Let's do some analysis here:
1) the perimeter of the triangle, which is given, is the sum of all 3 sides of the triangle.
2) the lengths of 2 of the sides are given.  If we sum those lengths up, and then subtract this sum from the given perimeter, we'll then have the length of the 3rd side.

This takes care of Parts A and B.