Find the equation of the line parallel to y-axis and drawn through the point of intersection of the lines `x-7y+5=0\ a n d\ 3x+y=0.`

Explanation

Equation of a line passing through the intersection of lines `x-7y+5=0` and `3x+y=0` is ltbr. `(x-7y+5)+lambda(3x+y)=0`
`implies x(1+3lambda)+y(lambda-7)+5=0` ………`(1)`
This line will be parallel to `y`-axis, if coefficient of `y=0`
`implies lambda-7=0implieslambda=7`
`:.` From equation `(1)`, required equation is
`x(1+21)+0+5=0`
`implies 22x+5=0`