So you subtract 4x from the right side witch then equals (4x+3)-3. Then you subtract 4x from the left side witch equals x+3)-3. Then you subtract 3 from the left side. Witch should equal x+(-3). Then you subtract 3 to the right side. Wich equal x+(-6). Then because x equals 1x. You device 1 by -6. Wich x+ -6
