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egracer

  • one year ago

The lengths of two sides of a triangle are shown below: Side 1: 3x2 − 2x − 1 Side 2: 9x + 2x2 − 3 The perimeter of the triangle is 5x3 + 4x2 − x − 3. 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) (I ONLY NEED HELP WITH PART B AND C)

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  1. welshfella
    • one year ago
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    Part A ; Just add 3x2 − 2x − 1 + 9x + 2x2 − 3 yes you are correct

  2. welshfella
    • one year ago
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    Part B ;- its perimeter - sum of other 2 sides = 5x^3 + 4x^2 − x − 3 - (5x^2+7x−4) = 5x^3 + 4x^2 - x - 3 - 5x^2 - 7x + 4 - note that you distribute the negative over the parentheses so some signs change

  3. welshfella
    • one year ago
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    = 5x^3 - x^2 - 8x + 1

  4. welshfella
    • one year ago
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    yes - note when you subtract polynomials first put the second one in parentheses

  5. welshfella
    • one year ago
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    Being closed under addition and subtraction means that the result os adding and subtracting polynomials results in another polynomial. And these 2 operations which we have done show that to be the case.

  6. welshfella
    • one year ago
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    *of not os

  7. egracer
    • one year ago
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    Thank you so much for your help! I finally understand how to do it now :)))

  8. welshfella
    • one year ago
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    yw

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