Lets say you have a question such as 7x+1=15.
First you have to start with the addition or subtraction because of PEMDAS. In order to get rid of the +1, you have to subtract 1 from it and do the same thing to the number on the other side of the equal sign.
7x+1-1=15-1
Which leaves you with
7x=14
What you want to do is get the variable by itself so, since the variable is basically multiplying itself by the coefficient, you want to divide the 7x by 7 to get rid of the coefficient. Make sure to do the same for both sides of the equation!
7x/7=14/7
x=2
Thats the answer.
Hopefully you can figure this out on your own problem.