Question

Given the polynomial 2x3 + 18x2 − 18x − 162, what is the value of the coefficient 'k' in the factored form?

2x3 + 18x2 − 18x − 162 = 2(x + k)(x − k)(x + 9)

k= ____________

Answer 1

Your Answer:

k = 3

Hope this helps y'all :)

Answer 2

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 :)