Q. Use synthetic division to determine whether or not (x+4) is a factor of (−4x3+21x2−4x−5).- Quotient: □ help (formulas)- Remainder: □ help (numbers)
Replace with root: To use synthetic division, replace (x+4) with its root, which is −4. Set up synthetic division with −4 and the coefficients of the polynomial −4x3+21x2−4x−5.
Set up synthetic division: Write down the coefficients: −4, 21, −4, −5. Bring down the first coefficient, −4, to the bottom row.
Write down coefficients: Multiply −4 by the root, which is −4, and write the result under the second coefficient.−4×−4=16.
Multiply and write result: Add the second coefficient, 21, and the result from the previous step, 16, to get 37. Write 37 in the bottom row.
Add and write result: Multiply the root, −4, by 37 and write the result under the third coefficient.−4×37=−148.
Multiply and write result: Add the third coefficient, −4, and the result from the previous step, −148, to get −152. Write −152 in the bottom row.
Add and write result: Multiply the root, −4, by −152 and write the result under the fourth coefficient.−4×−152=608.
Multiply and write result: Add the fourth coefficient, −5, and the result from the previous step, 608, to get 603. Write 603 in the bottom row. This is the remainder.
Add and write result: If the remainder is 0, then (x+4) is a factor of the polynomial.Since the remainder is 603, which is not 0, (x+4) is not a factor of the polynomial.