Are you solving this for x? You can't because the left side is eliminated by subtracting (1/2)x from (1/2)x. That leaves nothing on the left. [tex]0= \frac{-4}{x} [/tex] you can't solve that for x because when you multiply both sides by x, 0*x = 0 and [tex]0 \neq 4[/tex] I think you made a mistake in your typing or something...unless the answer was no solution!
