Theo đề, ta có hệ phương trình:
\(\left\{{}\begin{matrix}a\cdot0+b\cdot0+c=2017\\a+b+c=2018\\a-b+c=2020\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}c=2017\\a+b=1\\a-b=3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}c=2017\\a=2\\b=-1\end{matrix}\right.\)
\(f\left(x\right)=2x^2-x+2017\)
Khi x=-2 thì \(f\left(-2\right)=2\cdot4+2+2017=8+2+2017=2027\)