The equation of straight line is y = ax + b
Changing coordinates, we get
b = ax + y
Line 
x 
y 

1 
3 
4 
b = 3a+4 
2 
0 
4 
b = 4 
3 
1 
4 
b = a + 4 
4 
6 
12 
b = 6a + 12 
5 
4 
1 
b = 4a+1 
6 
1.5 
0 
b = 1.5a 
7 
1 
2 
b = 2a + 2 
8 
2 
3 
b = a3 
9 
3 
2 
b = 3a  2 
Plot the above obtained eq. of line on the graph paper and then find a point through which maximum number of lines pass
From the graph, we observe that 4 lines intersect a common point i.e. a = 2.7 & b = 4.
By using these values of a and b we can write another eq. of line in xyplane i.e. y = 2.7x – 4
Hence, four lines intersecting at one point in abplane means there are three points on one line in xyplane