Question

f) \(\dfrac{x+1}{x-3}=\dfrac{x+7}{x-2}\)

Answer 1

\(\dfrac{x+1}{x-3}=\dfrac{x+7}{x-2}\) ĐK : \(\left\{{}\begin{matrix}x-3\ne0\\x-2\ne0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x\ne3\\x\ne2\end{matrix}\right.\)

`=> (x+1)(x-2)=(x-3)(x+7)`

`=> x^2 -2x +x-2 = x^2+7x-3x-21`

`=> x^2 -x -2 = x^2+4x-21`

`=>x^2 -x-x^2-4x = -21+2`

`=> -5x = -19`

`=>x=19/5` (t/m)