Solve – 5 x – 4 y = 19 for y to obtain the slope: -5x - 19 = 4y, and so
the slope is (-5/4).
A line perpendicular to – 5 x – 4 y = 19 must have a slope which is the negative reciprocal of this (-5/4). That would be (+4/5).
Using the point-slope form of the eqn of a str line:
y-11 = (4/5)(x-[-5]), or (4/5)(x+5). This could, of course, be written in other (but equivalent) forms.
