Question

The expression $4x^2+16x+m$ is divisible by (x + 3). Then, m is a divisor of _____________.

• A. 4
• B. 16
• C. 20
• D. 12

Answer 1

Answer: (A), (D)

The correct options are
A 4
D 12

Let $f\left(x\right)=4x^2+16x+m$

$(x+3)$ is a factor of $f\left(x\right)$

$\Rightarrow$ $f(-3)=0$

$\Rightarrow$ $4(-3{)}^2+16(-3)+m=0$

$\Rightarrow$ $36-48+m=0$

$\Rightarrow$ $m=12$

$\therefore m$ is a divisor of both 4 and 12.

$\therefore$ Option A and D are correct.