Question

TÌM X

X^2<3X

HELPPPPPPPPPPPPPPPPPPPP MEEEEEEEE

Answer 1

Ta có: \(x^2< 3x\)

\(\Leftrightarrow x^2-3x< 0\)

\(\Leftrightarrow x\left(x-3\right)< 0\)

\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x>0\\x-3< 0\end{matrix}\right.\\\left\{{}\begin{matrix}x< 0\\x-3>0\end{matrix}\right.\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x>0\\x< 3\end{matrix}\right.\\\left[{}\begin{matrix}x< 0\\x>3\end{matrix}\right.\left(loại\right)\end{matrix}\right.\Leftrightarrow0< x< 3\)

Vậy: S={x|0<x<3}