Given
[tex]P(x)=x^3+4x^2-8[/tex]
To determine whether (x+2) is a factor of P(x), we find the value of P(-2). If P(-2)=0, then by factor theorem, we can say that (x+2) is a factor of P(x).
[tex]\begin{gathered} P(-2)=(-2)^3+4(-2)^2-8 \\ =-8+16-8 \\ =-16+16 \\ =0 \end{gathered}[/tex]
Hence (x+2) is a factor of P(x).
