When solving for a variable, we try to get the variable (we are solving for) on one side, usually the left hand side, and have the rest of the equation on the other side, usually on the right hand side, and you get your answer!
When looking at the equation 2x = 676 what could we do to get the 'x' variable alone? The first thing that comes out to me is to divide the left hand side by two. This will result in just 'x'.
And make sure that any operation you do on one side, make sure to do the same on the opposite side.
2x = 676
x = 676 / 2
x = 338
Hope this answer helps you and your quest at getting better at mathematics!