Official solution
Equation of lines;
px + qy + r = 0 . . . . . (1)
Also given
3p + 2q + 4r = 0 . . . . . . (2)
divide equation (2) by 4, we get
\[{3 \over 4}P + {2 \over 4}q + r = 0\] . . . . (3)
By comparing (1) and (3) we get,
x = \[{3 \over 4}\] and y = \[{2 \over 4}\] = \[{1 \over 2}\]
For any value of p,q and r, the equation of set of lines will pan through \[\left( {{3 \over 4},{1 \over 2}} \right)\]