The lengths of two sides of a triangle are shown. 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? Show your work. (4 points) Part B: What is the length of the third side of the triangle? Show your work. (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.  

B.  

C. See Explanation

Step-by-step explanation:

Given

Shape: Triangle

A.

Calculating the total length of the two sides;

Collect like terms

B.

Calculating the total length of the third side;

Length of the two sides is calculated in (A) above;

Open Bracket

Collect Like Terms

C.

Part A is close under addition because the result of the addition has the same exponent as the expressions added together

Part B is close under subtraction because the result of the subtraction also have the same exponent as the expressions that were subtracted

$450 is the answer.

step-by-step explanation:

30% of 450 = 135

450-135=315