x=6
Explanation
[tex]\begin{gathered} 2(x+2x)=36 \\ \end{gathered}[/tex]
Step 1
apply distributive property
[tex]\begin{gathered} 2(x+2x)=36 \\ 2x+4x=36 \\ \end{gathered}[/tex]Step 2
add similar terms
[tex]\begin{gathered} 2x+4x=36 \\ 6x=36 \end{gathered}[/tex]Step 3
finally, divide both sides by 6
[tex]\begin{gathered} \frac{6x}{6}=\frac{36}{6} \\ x=6 \end{gathered}[/tex]I hope this helps you