Question

Giúp em với ạ

Answer 1

c: Theo đề, ta có:

\(\left\{{}\begin{matrix}\dfrac{-b}{2a}=4\\4a+2b+c=-5\\a-b+c=16\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}b=-8a\\-12a+c=-5\\9a+c=16\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}c=1\\a=\dfrac{5}{3}\\b=-8\cdot\dfrac{5}{3}=-\dfrac{40}{3}\end{matrix}\right.\)