Question

The set of lines ax + by + c = 0, where 3a + 2b + 4c = 0 is concurrent at the point. . . .

Answer 1

The set of lines ax + by + c = 0, where 3a + 2b + 4c = 0

comparing the coefficients of x and y.

Thus, point of concurrency is (3/4 , 1/2)

Alternate Solution 

As; ax + by + c = 0, satisfy 3a + 2b + 4c = 0 which represents system of concurrent lines whose point of concurrency could be obtained by comparison as,