Mathorio
Answer key
Dividing Polynomials
Show your work for each problem.
- 1.Simplify:
- a)
- b)
- c)
- d)
Answer:
- 2.Simplify: . Enter the simplified form (e.g., 3x^2).
Answer: 3x^2
- 3.Simplify:
Answer: 4x + 2
- Divide the first term: = ? 4x
- Divide the second term: = ? 2
- Combine the results: 4x + 2
- 4.In synthetic division, what value of do you use to divide by ?
- a)
- b)
- c)
- d)
Answer:
For , we have . The sign in synthetic division is always opposite to what appears in the divisor.
- 5.Use polynomial long division to divide by .
Answer: x + 4
- Divide by : x
- Multiply by and subtract from . What remains? 4x
- Bring down . Now divide by : 4
- Multiply by and subtract from . What is the remainder? 0
- 6.Using the Remainder Theorem, what is the remainder when is divided by ?
- a)
- b)
- c)
- d)
Answer:
. Since the remainder is , is a factor of .
- 7.Divide by . Enter the quotient.
Answer: x - 3
. Dividing by gives with no remainder.
- 8.Use synthetic division to divide by .
Answer: x^2 + 4x + 3
- What value of do you use? 2
- Write the coefficients: . Bring down the 1. Multiply by 2 and add to 2: 4
- Multiply 4 by 2, add to -5: 3
- Multiply 3 by 2, add to -6. What is the remainder? 0
- 9.What is ?
- a)
- b)
- c)
- d)
Answer:
- 10.Divide by using long division.
Answer: 2x - 1
- Divide by : 2x
- Multiply by and subtract from . What remains? -x
- Bring down . Now divide by : -1
- Multiply by and subtract from . What is the remainder? 0
- 11.Use synthetic division to find the remainder when is divided by .
Answer: 0
Using : 3 | 1 -4 1 6 gives 1, -1, -2, 0. The remainder is 0, so is a factor.
- 12.Divide by using synthetic division. Remember to include zero coefficients!
Answer: x^2 + 2x + 4
- Write the polynomial with all terms. What are the coefficients? 1, 0, 0, -8
- Set up synthetic division with . After the first operation: 2
- Continue: 4
- Final step: . This is the remainder. 0
- 13.What is the quotient when is divided by ?
- a) (remainder -8)
- b) (remainder 0)
- c) (remainder 0)
- d) (remainder 8)
Answer: (remainder -8)
Using synthetic division with : We write 3, 5, -2, -8 (coefficients). Bring down 3. Then , add to 5 gives -1. Then , add to -2 gives 0. Then , add to -8 gives -8. The quotient is with remainder . Verify: ✓
- 14.Divide by . Enter the quotient polynomial.
Answer: x^3 + 2x^2 + 4x + 8
Using synthetic division: 2 | 1 0 0 0 -16 gives 1, 2, 4, 8, 0. Quotient: .
- 15.Divide by using polynomial long division.
Answer: 3x^2 + x - 5
- Divide by : 3x^2
- Multiply by : . Subtract from . What remains? 2x^2
- Bring down . Divide by : x
- Multiply by : . Subtract from . What remains? -10x
- Bring down . Divide by : -5
- Multiply by : . Subtract from . What is the remainder? 1