Find the value of p so that the three lines 3x + y – 2 = 0, px + 2 y – 3 = 0 and 2x – y – 3 = 0 may intersect at one point.

The equations of the given lines are


3x + y -2 = 0 ------ (1)


px + 2y – 3 = 0------(2)


2x – y – 3 = 0 ------ (3)


On solving equations (1) and (3), we get,


x = 1 and y = -1


Since, the three lines may intersect at one point, the point of intersection of lines (1) and (3) will also satisfy line (2).


p(1) + 2(-1) -3 = 0


=> p – 2 -3 = 0


=> p =5


Therefore, the required value of p is 5.


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