Given equation of lines are:

      x - 7y + 5 = 0

=> x - 7y + 5 = 0 .......1

      3x + y = 0 ...........2

After solving equation 1 and 2, we get

x = -5/22 and y = 15/22

Now the inetrsection point is (-5/22 ,  15/22)

Now Equation of aline passing through (a,b) and parallel to y-axis is x = a. 

So the equation of the line parallel to y-axis and drawn through the point of intersection of the lines x - 7y + 5 = 0 and 3x + y = 0 is x = -5/22

=> 22x = -5

=> 22x + 5 = 0