Which synthetic division shows how to find the quotient?

x5−4x3+2x+6÷x+2


(1 point)

1 answer

To perform synthetic division for the polynomial \( x^5 - 4x^3 + 2x + 6 \) by \( x + 2 \), we first rewrite \( x + 2 \) to find the root, which is \( -2 \).

  1. Set up the synthetic division:

    • The coefficients of the polynomial \( x^5 - 4x^3 + 2x + 6 \) are:
      • \( 1 \) (for \( x^5 \))
      • \( 0 \) (for \( x^4 \), since there's no \( x^4 \) term)
      • \( -4 \) (for \( x^3 \))
      • \( 0 \) (for \( x^2 \), since there's no \( x^2 \) term)
      • \( 2 \) (for \( x^1 \))
      • \( 6 \) (for the constant term)

    The coefficients are \([1, 0, -4, 0, 2, 6]\).

  2. Write down the synthetic division setup:

    • The root \( -2 \) is placed on the left, and the coefficients are lined up on the right:
    -2 |  1   0   -4   0   2   6
       |      
       |_________________________
    
  3. Start the synthetic division process:

    • Bring down the leading coefficient \( 1 \):
    -2 |  1   0   -4   0   2   6
       |        
       |_________________________
         1              
    
    • Now multiply \( 1 \) by \( -2 \) and add to the next coefficient \( 0 \):
    -2 |  1   0   -4   0   2   6
       |      -2           
       |_________________________
         1  -2              
    
    • Next, multiply \( -2 \) by \( -2 \) and add to the next coefficient \( -4 \):
    -2 |  1   0   -4   0   2   6
       |      -2   4      
       |_________________________
         1  -2   0         
    
    • Next, multiply \( 0 \) by \( -2 \) and add to the next coefficient \( 0 \):
    -2 |  1   0   -4   0   2   6
       |      -2   4   0   
       |_________________________
         1  -2   0   2      
    
    • Next, multiply \( 2 \) by \( -2 \) and add to the next coefficient \( 6 \):
    -2 |  1   0   -4   0   2   6
       |      -2   4   0   -4
       |_________________________
         1  -2   0   2   2
    
  4. Finalize the synthetic division:

    • The resulting row represents the coefficients of the quotient polynomial and the remainder. The quotient polynomial is: \[ x^4 - 2x^3 + 0x^2 + 2x + 2 \]
    • The remainder is \( 2 \).

Thus, the final result of the synthetic division is: \[ \text{Quotient: } x^4 - 2x^3 + 2x + 2 \quad \text{Remainder: } 2 \]

To summarize: \[ \frac{x^5 - 4x^3 + 2x + 6}{x + 2} = x^4 - 2x^3 + 2x + 2 + \frac{2}{x + 2} \]