Question

If x=-5+$\sqrt{-4}$, then the value of the expression $x^4$+9$x^3$+35$x^2$-x+4 is

• A. 160
• B. -160
• C. 60
• D. -60

Answer 1

The correct option is B

-160

x+5 =4i $\Rightarrow$ $x^2$+10x+25=-16

Now, $x^4$+9$x^3$+35$x^2$-x+4

=($x^2$+10x+41)($x^2$-x+4)-160=-160