a) \(\left(x-3\right)\left(4-5x\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-3=0\\4-5x=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=3\\x=\frac{4}{5}\end{cases}}\)
Vậy \(x\in\left\{3;\frac{4}{5}\right\}\)
b) \(\left(9x-1\right):0,16=9:\left(x-1\right)\)
Đề sai chắc chắn lun
(x-1):0,16=9:(x-1) đề này ms đúng hen ghi đè xai mất chiu
b) \(\left(x-1\right):0,16=9:\left(x-1\right)\)
\(\Leftrightarrow\frac{x-1}{0,16}=\frac{9}{x-1}\)
\(\Leftrightarrow\left(x-1\right)^2=9.0,16\)
\(\Leftrightarrow\left(x-1\right)^2=\frac{36}{25}\)
\(\Leftrightarrow\left(x-1\right)^2-\frac{36}{25}=0\)
\(\Leftrightarrow\left(x-1\right)^2-\left(\frac{6}{5}\right)^2=0\)
\(\Leftrightarrow\left(x-1-\frac{6}{5}\right)\left(x-1+\frac{6}{5}\right)=0\)
\(\Leftrightarrow\left(x-\frac{11}{5}\right)\left(x+\frac{1}{5}\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-\frac{11}{5}=0\\x+\frac{1}{5}=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{11}{5}\\x=\frac{-1}{5}\end{cases}}\)
Vậy \(x\in\left\{\frac{11}{5};\frac{-1}{5}\right\}\)
