Which synthetic division shows how to find the quotient?

2x3−2x2+6x−4÷x−2

(1 point)

1 answer

To perform synthetic division for the polynomial \(2x^3 - 2x^2 + 6x - 4\) by \(x - 2\), we will use 2 (the zero of \(x - 2\)) in the synthetic division process. Here's how to set it up and perform the division:

  1. Write down the coefficients of the polynomial. For \(2x^3 - 2x^2 + 6x - 4\), the coefficients are:

    • \(2\) (for \(2x^3\))
    • \(-2\) (for \(-2x^2\))
    • \(6\) (for \(6x\))
    • \(-4\) (for the constant term)
  2. Set up the synthetic division:

    2 |  2   -2   6   -4
       |_________________
    
  3. Bring down the leading coefficient (2):

    2 |  2   -2   6   -4
       |_________________
         |  2
    
  4. Multiply the value you've just brought down (2) by 2 (the number outside) and write the result under the next coefficient:

    2 |  2   -2   6   -4
       |      4
       |_________________
         |  2   2
    
  5. Add the column: \(-2 + 4 = 2\)

    2 |  2   -2   6   -4
       |      4   4
       |_________________
         |  2   2  10
    
  6. Repeat the multiplication and addition for the next column:

    • Multiply \(2\) (the last result) by \(2\) (the number outside): \(2 \times 2 = 4\)
    • Add: \(6 + 4 = 10\)
    2 |  2   -2   6   -4
       |      4   4  20
       |_________________
         |  2   2  10
    
  7. Finally, multiply \(10\) by \(2\): \(10 \times 2 = 20\) and add: \(-4 + 20 = 16\)

    2 |  2   -2   6   -4
       |      4   4  20
       |_________________
         |  2   2  10  16
    

The final row (the bottom row) gives us the coefficients of the quotient and the remainder:

  • The quotient is \(2x^2 + 2x + 10\)
  • The remainder is \(16\)

Thus, the result of \(2x^3 - 2x^2 + 6x - 4\) divided by \(x - 2\) using synthetic division is:

\[ 2x^3 - 2x^2 + 6x - 4 = (x - 2)(2x^2 + 2x + 10) + 16 \]