Question

The expression $2x^3+x^2-2^x-1$ is divisible by

• A. 2x + 3
• B. 2x + 1
• C. 2x - 3
• D. 2x – 1

Answer 1

Answer:

B. 2x + 1

2x³ + x² – 2x – 1

⇒ x²(2x + 1) – (2x + 1)

⇒ (2x + 1) (x² – 1)

∴ The expression 2x³+ x²– 2x – 1 is divisible by (2x + 1)