Find the equation of line parallel to the y- axis and drawn through the point of intersection of x−7y=−5 and 3x+y−7=0.
The equation of any line through the point of interection of the given lines is of the form,
x−7y+5k(3x+y−7)=0i.e.(1+3k)x+(k−7)y+5−7k=0
IF this line is parallel to Y - axis, then the coefficeint of y should be zero,
i.e. k−7=0⇒k=7
On putting the value of k = 7 in Eq. (i), we get,
(1+3×7)x+0+5−7×7=022x−44=0∴x−2=0,Which is required equation.