Question

Tìm x :

\(\left(2x-3\right)^2\)=121

Answer 1

\((2x-3)^2=121\\\Rightarrow(2x-3)^2=(\pm11)^2\)

\(\Rightarrow\left[{}\begin{matrix}2x-3=11\\2x-3=-11\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x=14\\2x=-8\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=7\\x=-4\end{matrix}\right.\)

Vậy: \(x\in\left\{7;-4\right\}\).

Answer 2

Chi tiết giúp mình nhé.Mình cảm ơn

 

Answer 3

(2\(x\) - 3)² = 121

(2\(x\) - 3)² = 11²

\(\left[{}\begin{matrix}2x-3=-11\\2x-3=11\end{matrix}\right.\)

 \(\left[{}\begin{matrix}2x=-11+3\\2x=11+3\end{matrix}\right.\)

  \(\left[{}\begin{matrix}2x=-8\\2x=14\end{matrix}\right.\)

     \(\left[{}\begin{matrix}x=-8:2\\x=14:2\end{matrix}\right.\)

      \(\left[{}\begin{matrix}x=-4\\x=7\end{matrix}\right.\)

       vậy \(x\) \(\in\) {-4; 7}