`(x+1)/(4)=(9)/(x+1)` `(ĐK:x\ne -1)`
`=>(x+1)^{2}=4.9`
`=>(x+1)^{2}=36=(+-6)^{2}`
`=>x+1=6` hoặc `x+1=-6`
`=>x=5` hoặc `x=-7` (TMDK)
\(đkx\ne-1\\ \dfrac{\left(x+1\right)^2}{4\left(x+1\right)}=\dfrac{9.4}{4\left(x+1\right)}\\ \left(x+1\right)^2=36\\ \left[{}\begin{matrix}x+1=6\\x+1=-6\end{matrix}\right.=>x=5\left(thoaman\right);x=-7\left(thoaman\right)\)
`(x+1)/4 = 9/(x+1)`
`-> (x+1)^2 = 36`
`->` \(\left[{}\begin{matrix}x+1=6\\x+1=-6\end{matrix}\right.\)
`->` \(\left[{}\begin{matrix}x=5\\x=-7\end{matrix}\right.\)
