Làm giúp `2` câu, có tâm hộ em với =) `c) {-x}/4 = {-9}/x` `d) {2-x}/16 = {-4}/{x-2}`

`Answer:`

`c)`` {-x}/4 = {-9}/x`

`->-x.x=4.(-9)`

`->-x^2=(-36)`

`->-x^2=-6^2`

`->`\(\left[ \begin{array}{l}x=6\\x=-6\end{array} \right.\) 

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

`d)`` {2-x}/16 = {-4}/{x-2}`

`->(2-x).(x-2)=(-4).16`

`->-(x-2)^2=(-64)`

`->(x-2)^2=-8^2`

`->x-2=`\(\left[ \begin{array}{l}x=8\\x=-8\end{array} \right.\) 

`->x=`\(\left[ \begin{array}{l}x=10\\x=-6\end{array} \right.\) 

Vậy \(\left[ \begin{array}{l}x=10\\x=-6\end{array} \right.\) 

`#Boy`