How do you begin isolating the variable x to one side of the equation?

When you isolate the variable to one side of the equation, you have to use the given operation to simplify the number on the other side of the equal sign.

Ex: 4x + 8 = 40

This is a simple one-step equation, but to solve this, first, you need to subtract 8 from 40. 

4x = 40
       -  8

4x = 32

Then, you divide 4x by 32.

4x = 32
4x     4
   
  x = 8

However, with multi-step equations you have to do these three important steps.

1.) Distribute - the number that's on the outside of the parentheses, gets multiplied to all the numbers except for the one on the right side of the equal sign

2.) Combine Like Terms - numbers with coefficients like 3x, 6y, or 7a, that have another one like it, you need to add them together and keep the variable. 

3.) Simplify - it's almost like combining like terms, except if you have more than one number with coefficient, then again, add all the numbers with the same variable together. 

And by the way, coefficient basically is a "fancy" way to say "number with a variable attached".

I hope I helped :)