3(x-4)+6(x-1)=90

Solution for 3(x-4)+6(x-1)=90 equation:

3(x-4)+6(x-1)=90

We simplify the equation to the form, which is simple to understand 
3(x-4)+6(x-1)=90

Reorder the terms in parentheses
+(+3x-12)+6*(x-1)=90

Remove unnecessary parentheses
+3x-12+6+*(+x-1+)=+90

Reorder the terms in parentheses
+3x-12+(+6x-6)=90

Remove unnecessary parentheses
+3x-12+6x-6=+90

We move all terms containing x to the left and all other terms to the right. 
+3x+6x=+90+12+6

We simplify left and right side of the equation. 
+9x=+108

We divide both sides of the equation by 9 to get x. 
x=12