Question

[đỗ thị kiều trinh]

tìm số hữu tỉ x biết :

a)|1-2x|>7

b)\(\frac{-5}{x-3}< 0\)

c)\(\left(x-2\right)\left(x+2\right)\left(4-x\right)\left(x-1\right)^2\) \(\le0\)

Answer 1

[Nguyen Thi Trinh]

a/ \(\left|1-2x\right|>7\Leftrightarrow\left[{}\begin{matrix}1-2x=7\\1-2x=-7\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}2x< -6\\2x< 8\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x< -3\\x< 4\end{matrix}\right.\)

b/ \(\dfrac{-5}{x-3}< 0\Leftrightarrow x-3>0\) ( vì -5<0)

\(\Leftrightarrow x>3\)

Answer 2

[Nguyễn Hà Khắc]

sao ko trả lời câu c