Divide the polynomial n^3 + 7n^2 + 14n + 3 by (n + 2) to determine the quotient and the remainder. (1 point)

A. The quotient is n^2 - 3n + 11 and the remainder is 6.
B. The quotient is n^2 - 3n + 11 and the remainder is -5.
C. The quotient is n^2 + 5n + 4 and the remainder is 6.
D. The quotient is n^2 + 5n + 4 and the remainder is -5

1 answer

To divide the polynomial \( n^3 + 7n^2 + 14n + 3 \) by \( n + 2 \), we can use polynomial long division.

  1. Divide the leading term: Divide the leading term of the dividend \( n^3 \) by the leading term of the divisor \( n \): \[ \frac{n^3}{n} = n^2 \]

  2. Multiply and subtract: Multiply \( n^2 \) by the entire divisor \( n + 2 \) and subtract from the original polynomial: \[ n^3 + 7n^2 + 14n + 3 - (n^2(n + 2)) = n^3 + 7n^2 + 14n + 3 - (n^3 + 2n^2) = 5n^2 + 14n + 3 \]

  3. Repeat the process: Now take \( 5n^2 \) and divide by \( n \): \[ \frac{5n^2}{n} = 5n \]

    Multiply \( 5n \) by \( n + 2 \): \[ 5n(n + 2) = 5n^2 + 10n \] Subtract this from \( 5n^2 + 14n + 3 \): \[ 5n^2 + 14n + 3 - (5n^2 + 10n) = 4n + 3 \]

  4. Repeat again: Now take \( 4n \) and divide by \( n \): \[ \frac{4n}{n} = 4 \]

    Multiply 4 by \( n + 2 \): \[ 4(n + 2) = 4n + 8 \] Subtract this from \( 4n + 3 \): \[ 4n + 3 - (4n + 8) = 3 - 8 = -5 \]

  5. Conclusion: We have finished dividing. The quotient is: \[ n^2 + 5n + 4 \] and the remainder is: \[ -5 \]

Thus, the answer is: D. The quotient is \( n^2 + 5n + 4 \) and the remainder is -5.