Question

The 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)

Answer 1

Your thoughts/answer?

Answer 2

Part A I believe is 7x^2 + 2x +1

Answer 3

@Blueberries1516

Answer 4

That is what I calculated.

Answer 5

Part B?

Answer 6

You have to subtract the two sides from the perimeter to get the 3rd side.

Answer 7

Example:
x = 3, because you subtract do 6 - (1+2), or 6 - 3.

Answer 8

So knowing that, can you figure out what to do?

Answer 9

Yes thankyou so much!

Answer 10

Great what did you get?

Answer 11

4x^3 - 10x^2 - 7

Answer 12

Yes that's right