First, you need to get x by itself, so you'll add 2 to both sides of the equal sides which will cancel the -2 and leave 4x by itself:
4x-2=2x-10
+2 +2
4x=2x-8
Next, you'll subtract the 2x from both sides, leaving the -8 by itself.
4x = 2x -8
-2x -2x
2x= -8
Finally, you'll divide both sides by the coefficient of 2x, which is 2. That leaves you with x= -2