The straight lines 4ax + 3by + c = 0, where a + b + c = 0, are concurrent at the point
(4, 3)
(1/4, 1/3)
(1/2,1/3)
None of these
The set of lines is 4ax + 3by + c = 0, where a + b + c = 0.
Eliminating c, we get
4ax+3by−(a+b)=0 or a(4x−1)+b(3y−1)=0
This passes through the intersection of the lines 4x - 1 = 0
and 3y−1=0 , i.e., x=1/4,y=1/3 , i.e., (1/4,1/3) .