Explanation:
The given line is
2x + 14y = 28 ......i)
Let the line perpendicular to I) be
14x - 2y + k = 0 ......ii)
As line II) passes through point ( - 7 , 8) we get
14 * ( -7) - 2 * 8 + k = 0
- 98 - 16 + k = 0
- 144 + k = 0
k = 144
Hence the required equation is
14x - 2y + 144 = 0
2y = 14x + 144
y = ( 14x + 144) / 2
y = 7x + 72
Hope it will help :)