Question

giải hộ mình bài này đi ạ....

4/x=x/9

Answer 1

\(\frac{4}{x}=\frac{x}{9}\)

\(\Rightarrow\)\(x\cdot x=4\cdot9\)

\(\Rightarrow x^2=36\)

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

\(\Rightarrow\)\(\left[{}\begin{matrix}x=6\\x=-6\end{matrix}\right.\)

Vậy \(x\in\left\{6;-6\right\}\)

Answer 2

Ta có:
\(\frac{4}{x}=\frac{x}{9}\)

\(\Rightarrow x.x=4.9\)

\(\Leftrightarrow x^2=36=6^2=\left(-6\right)^2\)

Vậy: \(\left[{}\begin{matrix}x=6\\x=-6\end{matrix}\right.\)