Prove that the following sets of three lines are concurrent: `15 x-18 y+1=0,\ 12 x+10 y-3=0\ a n d\ 6x+66 y-11=0.`

Explanation

Given: `15x – 18y + 1 = 0 …… (i) `

`12x + 10y – 3 = 0 …… (ii)`

` 6x + 66y – 11 = 0 …… (iii)`

Now, consider the following determinant:
=`|[15,-18,1],[12,10,-3],[6,66,-11]|`

`=15(-110+198)+18(-132+18)+(792-60)`

`=0`