Answer:
Step-by-step explanation:
Alright, lets get started.
\(2x^3 + 18x^2 -18x -162 = 2(x+k)(x-k)(x+9)\)
\(2(x+k)(x-k)(x+9) =2x^3 + 18x^2 -18x -162\)
\(2(x^2-k^2)(x+9)=2x^3 + 18x^2 -18x -162\)
\(2(x^3+9x^2-k^2 x+9k^2)=2x^3 + 18x^2 -18x -162\)
\(2x^3 + 18x^2 -2k^2x+18k^2= 2x^3 + 18x^2 -18x -162\)
comparing both sides
\(2k^2 =18\)
\(k^2=9\)
\(k=3\)
hence answer is k = 3(plus/minus) : Answer
Hope it will help :)
