In the solution they have done $V_2 -V_1 = V_2 -V_3$

But I want to know can we solve it by taking $$V_1 -V_3=0$$ $$V_1 = V_3$$

from that we will get $$\frac{-x(3d)}{A\epsilon}= \frac{(x-5Q)(3d)}{A\epsilon}$$ $$ -x=5Q+x$$

But using that I am not getting the answer .