Question

If $x^3+3x^2-9x+c$ is of the form $(x-\alpha {)}^2(x-\beta )$, then $c$ is equal to

• A. $27$
• B. $-27$
• C. $5$
• D. $-5$

Answer 1

Answer: (B), (C)

The correct options are
B $-27$
C $5$

In $x^3+3x^2-9x+c$
For $c=-27$
$x^3+3x^2-9x-27={(x+3)}^2(x-3)$
And for $c=5$
$x^3+3x^2-9x+5={(x-1)}^2(x+5)$

And for other options this condition is not true.