[tex]\huge\boxed{x=-\frac{11}{2}}[/tex]
Start by distributing the [tex]-3[/tex] to the [tex](3+x)[/tex]. [tex]-3(3) + (-3)(x) + (x-6) = -4[/tex]
Multiply and simplify. [tex]-9-3x+(x-6)=-4[/tex]
Rearrange the terms. [tex]-3x+x-9-6=-4[/tex]
Combine like terms. [tex]-2x-15=-4[/tex]
Add [tex]15[/tex] on both sides. [tex]-2x=11[/tex]
Divide both sides of the equation by [tex]-2[/tex]. [tex]x=\boxed{-\frac{11}{2}}[/tex]