Giúp em câu e , f tìm x ạ cảm ơn mn

Đáp án:

 `e)`

`(2x+5)/(-3)=(-27)/(2x+5)`

`=>(2x+5)^2=(-3).(-27)`

`<=>(2x+5)^2=81=9^2=(-9)^2`

\(\left[ \begin{array}{l}2x+5=9\\2x+5=-9\end{array} \right.\) 

\(\left[ \begin{array}{l}2x=4\\2x=-14\end{array} \right.\) 

 \(\left[ \begin{array}{l}x=2\\x=-7\end{array} \right.\) 

`----------------`

`f)`

`1/6-1/3(x-1/2)^2=(-1)/6`

`1/3(x-1/2)^2=1/6-(-1/6)`

`1/3(x-1/2)^2=1/3`

`(x-1/2)^2=1/3:1/3`

`(x-1/2)^2=1=1^2=(-1)^2`

\(\left[ \begin{array}{l}x-\dfrac{1}{2}=1\\x-\dfrac{1}{2}=-1\end{array} \right.\)

\(\left[ \begin{array}{l}x=\dfrac{3}{2}\\x=\dfrac{-3}{2}\end{array} \right.\)