THe key to these types of problems is to remember that we can add, subtract, multiply or divide from one side of the equation as long as we do it to the other side as well. Example:
X+4=24 Can be rewritten as:
X+4-4=24-4 we can then solve the known portions of this equation
X+4-4 = X and 24-4 = 20
So it would look something like this if you showed all of your work
Hope this helps and if you have questions, I would be happy to help.