Side1 : 3x^2 − 4x − 1 (^to the second power) Side2: 4x − x^2 + 5 (^to the second power)
Perimeter of the triangle is: 5x^3 -2x^2+3x-8 (^to the second power)

Please Explain:
Part A: What is the total lenge of sides 1 and 2 of the triangle?
Part B: What is the length of the 3rd side of traingle?
Part C: Is Part A and Part B identify the polynomials are closed under addition and subtraction-please show math