Ok let's say we have
Then let's try to get the x's and the numbers on different sides. In this case we will subtract the 2x from the left and right and add the 5 to the left and right then we will get our conclusion.
You can always plug that value back into the equation to make sure you got it right.
Here are a few others you can try.
(There's a little bit of a shortcut on this one see if you can notice it)