Đặt \(P\left(x\right)=2x^3-3x^2+ax+b\)
Do \(P\left(x\right)⋮\left(x-1\right)\Rightarrow P\left(1\right)=0\Rightarrow a+b-1=0\)
Do \(P\left(x\right)\) chia \(x+2\) dư 3 \(\Rightarrow P\left(-2\right)=3\Rightarrow-2a+b-28=3\)
\(\Rightarrow\left\{{}\begin{matrix}a+b=1\\-2a+b=31\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}a=-10\\b=11\end{matrix}\right.\)