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(x³ - 13x² + 40x + 18) ÷ (x - 7)

A. (x² - 6x - 2)
B. (x² - 5x + 3)
C. (x² - 7x - 3)
D. (x² - 4x + 2)

1 Answer

4 votes

Final answer:

The polynomial (x³ - 13x² + 40x + 18) can be divided by (x - 7) using synthetic division to yield the quotient (x² - 6x - 2), making the correct answer A.

Step-by-step explanation:

The question is asking for the division of a polynomial by a binomial, which is a basic operation in algebra. The polynomial (x³ - 13x² + 40x + 18) needs to be divided by the binomial (x - 7). To find the answer, one can either use polynomial long division or synthetic division. Both methods will yield the quotient of the division.

To demonstrate, we'll use synthetic division:

  1. Set up the synthetic division by writing down the coefficients of the polynomial, which are 1, -13, 40, and 18, and the root of the binomial which is 7.
  2. Bring down the first coefficient, which is 1.
  3. Multiply the root by the new quotient's coefficient, and write the result under the next coefficient. For the first step, we multiply 1 by 7 to get 7, and write it under -13.
  4. Add the numbers in the second column to get the new coefficient, which is -13 + 7 = -6.
  5. Continue this process for all coefficients. Multiply 7 by the new quotient's coefficient, -6, to get -42; write this under 40, then add to get -2. Next, multiply -2 by 7 to get -14 and write this under 18, then add to get 4.
  6. As a result, the quotient is (x² - 6x - 2), with a remainder of 4.

The correct answer is A. (x² - 6x - 2) plus the remainder should be written as (x² - 6x - 2) + 4/(x - 7).

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