Answer:
p(x) = (x - 5)(x + 1)(x + 4)
General Formulas and Concepts:
Algebra I
- Terms/Coefficients
- Factoring
Algebra II
- Factoring Cubes:
- Long Division
- Synthetic Division
Explanation:
*Note:
Please excuse my bad handwriting :)
Step 1: Define
Identify
p(x) = x³ - 21x - 20
Linear factor (x - 5)
Step 2: Factor
Option 1: Factoring cubes formula
- Factor [Factoring Cubes]: p(x) = (x - 5)(x² + 5x + 4)
- Factor: p(x) = (x - 5)(x + 4)(x + 1)
Option 2: Long Division
See Attachment
Option 3: Synthetic Division
See Attachment #2