Answer:
[tex]x=-6[/tex]
Step-by-step explanation:
[tex]-6-3\left(2x+4\right)=18[/tex]
Add 6 to both sides:
[tex]-6-3\left(2x+4\right)+6=18+6[/tex]
[tex]-3\left(2x+4\right)=24[/tex]
Divide both sides by -3:
[tex]\frac{-3\left(2x+4\right)}{-3}=\frac{24}{-3}[/tex]
[tex]2x+4=-8[/tex]
Subtract 4 from both sides:
[tex]2x+4-4=-8-4[/tex]
[tex]2x=-12[/tex]
Divide both sides by 2:
[tex]\frac{2x}{2}=\frac{-12}{2}[/tex]
[tex]x=-6[/tex]