3(x+4)=36
What you need to do is divide both sides of the equation by 3 in the first part
x+4=12
Now you move the constant towards the right side and change the sign
x=12-4
Subtract the numbers to find the answer
x=8, therefore to solve 3(x+4)=36 it will give you x=8 as your answer. Hope this helps ^^