Question

\(\dfrac{x-3}{12}=\dfrac{3}{x-3}\)

Answer 1

\(\dfrac{x-3}{12}=\dfrac{3}{x-3}\)

\(\Rightarrow\left(x-3\right)^2=36\)

\(\Rightarrow x-3=6\)

\(\Rightarrow x=9\)

Answer 2

\(\dfrac{x-3}{12}=\dfrac{3}{x-3}\)

⇒ ( x-3 ) . ( x-3 ) = 12.3

⇒ ( x - 3)² = 36

⇒ ( x - 3 )² = 6²

⇒ x -3 = 6 hoặc x -3 = -6

* nếu x - 3 = 6

x=6+3

x=9

* nếu x - 3 = -6

x = -6 + 3

x= -3

Answer 3

Theo đề ta có:

\(\dfrac{x-3}{12}=\dfrac{3}{x-3}\)

=> (x-3) . (x-3) = 12.3

=> (x-3). (x-3) = 36

=> \(\left(x-3\right)^2\)= 36

=> \(\left(x-3\right)^2\)= \(6^2\)

=> \(\left[{}\begin{matrix}x-3=6\\x-3=-6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=6+3\\x=-6+3\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=9\\x=-3\end{matrix}\right.\)