Question

Tìm x

x-1/18=2/x-1

Answer 1

\(\dfrac{x-1}{18}=\dfrac{2}{x-1}\)

\(\Leftrightarrow\left(x-1\right)\left(x-1\right)=2.18\)

\(\Leftrightarrow\left(x-1\right)^2=36\)

\(\Leftrightarrow\left(x-1\right)^2=6^2=\left(-6\right)^2\)

\(\Leftrightarrow\left[{}\begin{matrix}x-1=6\\x-1=-6\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-5\end{matrix}\right.\)

Vậy ..

Answer 2

\(\dfrac{x-1}{18}=\dfrac{2}{x-1}\)

⇔ (x-1)(x-1)=18.2

⇔ (x-1)²=36

⇔ \(\left\{{}\begin{matrix}x-1=6\\x-1=-6\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=7\\x=-5\end{matrix}\right.\)