Có \(g\left(x\right)=x^2-3x+2=x\left(x-1\right)-2\left(x-1\right)=\left(x-2\right)\left(x-1\right)\)
\(f\left(x\right)⋮g\left(x\right)\)
\(\Leftrightarrow\left\{{}\begin{matrix}f\left(2\right)=0\\f\left(1\right)=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}16-2.8+4+2a+b=0\\1-3+1+a+b=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}2a+b=-4\\a+b=1\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}a+b=1\\a=-5\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}a=-5\\b=6\end{matrix}\right.\)
Hình như bạn viết sai đề?