Question

-4x^2-7x=0 -5x(x-2)+4=2 phần 7

Answer 1

bruh

Answer 2

a) Ta có: \(-4x^2-7x=0\)

\(\Leftrightarrow x\left(-4x-7\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\-4x-7=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\-4x=7\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{-7}{4}\end{matrix}\right.\)

Vậy: \(S=\left\{0;-\dfrac{7}{4}\right\}\)