The equation can be written:
(x-7)(x+7)/(2x-1)=-(x-7)2/(2x-1), 2x-1 and 1-2x are opposites, that is, 2x-1=-(1-2x).
x+7=-(x-7)=7, because terms x-7 and 2x-1 cancel out.
x=0 is the only value of x to satisfy the equation, so the "domain" is zero. There is no other variable (no dependent variable). LCD=1 (the absolute value of 2x-1 when x=0).