Explanation:
so we basically simplify the equation to the form, which is simple to understand 
2/3(x+6)=-18 then Reorder the terms in parentheses
+( + 0.66666666666667x+4)=-18 after that 
Remove unnecessary parentheses
 + 0.66666666666667x+4=-18 then We move all terms containing x to the left and all other terms to the right. 
 + 0.66666666666667x=-18-4 so We simplify left and right side of the equation. 
 + 0.66666666666667x=-22 We divide both sides of the equation by 0.66666666666667 to get x. 
x=-33 get it?