Verified Answer :

caylus

Hello,

x^3-4x²-12x+9=x^3+2x²-6x²-12x+9
=x²(x+2)-6x(x+2)+9
=(x+2)(x²-6x)+9

Remainder is 9

Answer:

9


Step-by-step explanation:

This is a straightforward application of the Remainder Theorem, which states that any polynomial \(p(x)\) , when divided by a linear factor \((x-a)\)  will have a remainder equal to evaluating the function \(p(x)\)  at \(x=a\)

To find the remainder of  \(x^{3}-4x^{2}-12x+9\)  when divided by  \((x+2)\)  , we have to evaluate the polynomial at \(x=-2\)

Let's do it.

\((-2)^{3}-4(-2)^{2}-12(-2)+9\\=9\)

Hence, 9 is the remainder.