a)\(P\left(x\right)=x^2-8x+6\)
b)bậc : 2
HSCN:6
HSTD: 6
c)\(P\left(0\right)=0-0+6=6\)
\(P\left(-\dfrac{1}{3}\right)=\left(-\dfrac{1}{3}\right)^2+8.\left(-\dfrac{1}{3}\right)+6=\dfrac{1}{9}-\dfrac{8}{3}+6=\dfrac{31}{9}\)
d)\(=>A\left(x\right)=P\left(x\right)-Q\left(x\right)\)
\(A\left(x\right)=x^2-3x-x^2+8x-6=11x-6\)
e) cho P(x) =0
\(=>x^2-3x=0\Rightarrow x\left(x-3\right)=0\Rightarrow\left[{}\begin{matrix}x=0\\x=3\end{matrix}\right.\)