Respuesta :

On the left side, you can condense the logarithms into one:

[tex]\ln(1-x)-\ln(3x+5)=\ln\dfrac{1-x}{3x+5}[/tex]

Then

[tex]\ln\dfrac{1-x}{3x+5}=\ln(1-6x)\implies e^{\ln((1-x)/(3+5))}=e^{\ln(1-6x)}\implies\dfrac{1-x}{3x+5}=1-6x[/tex]

From here it's a purely algebraic equation. Multiply both sides by [tex]3x+5[/tex] to get

[tex]1-x=(1-6x)(3x+5)[/tex]

[tex]1-x=5-27x-18x^2[/tex]

[tex]18x^2+26x-4=0[/tex]

[tex]9x^2+13x-2=0[/tex]

By the quadratic formula,

[tex]x=\dfrac{-13\pm\sqrt{241}}{18}[/tex]

or about [tex]x\approx-1.5847[/tex] and [tex]x\approx0.14023[/tex].

Before we finish, first note that in order for the original equation to make sense, we need [tex]x[/tex] to satisfy 3 conditions:

[tex]-x+1>0\implies x<1[/tex]

[tex]3x+5>0\implies x>-\dfrac53\approx-1.67[/tex]

[tex]-6x+1>0\implies x<\dfrac16\approx0.17[/tex]

or taken together,

[tex]-\dfrac53<x<\dfrac16[/tex]

so both solutions found above are valid.