Question

find the equation of the line perpendicular to 4y=x+3 that passes through the point (4,4)

Answer 1

4y=x+3
y=1/4x +3/4
as perpendicular, gradient is flipped and made into a minus. so is -4.
y=-4x +c
substitute values in to find c
4=-4 (4)+c
4=-16+c
c=20
y=-4x +20