1 . a3-21a-20

• A. a+1
• B. a-1
• C. a+2
• D. a-2

Answer: Option A

Explanation:

2 . a3-21a-20

• A. $\left(a-5\right)$
• B. $\left(a+1\right)$
• C. $\left(a+4\right)$
• D. $\left(a+2\right)$

Answer: Option D

Explanation:

3 . a3-21a-20

• A. (a+2)
• B. (a-2)
• C. (a+1)
• D. (a-1)

Answer: Option C

Explanation: