Question

(5-x)/9= -4/(x-5) tìm x

Answer 1

\(\dfrac{5-x}{9}=\dfrac{-4}{x-5}\left(x\ne5\right)\)

\(< =>\dfrac{5-x}{9}=\dfrac{4}{5-x}\)

suy ra

`(5-x)^2=36`

`<=>5-x=6` hoặc `5-x=-6`

`<=>x=5-6` hoặc `x=5-(-6)`

`<=>x=-1(tm)` hoặc `x=11(tm)`

 

Answer 2

\(\dfrac{5-x}{9}=-\dfrac{4}{x-5}\)

\(\Rightarrow\left(5-x\right)\left(x-5\right)=-4.9\)

\(\Rightarrow5x-25-x^2+5x+36=0\)

\(\Rightarrow-x^2+10x+11=0\)

\(\Rightarrow\left\{{}\begin{matrix}x=11\\x=-1\end{matrix}\right.\)