Question 819546
We want a line perpendicular to y=4x+5.
The slope needs to be the negative inverse of
the original equation. The negative inverse
of 4 is -1/4. (4)(-1/4)=1.
Using y = mx + b as a template,
and the point (4,-3) we will
substitute -1/4 for m, 4 for x, and -3 for y.
      -3 = (-1/4)(4) + b
      -3 =  -1 + b
add 1 to each side.
      -2 = b
So our equation is y = (-1/4)x -2