(-1,3) to the line 3x-4y-16=0

The equation of the straight line perpendicular to the given straight line

3x-4y-16=0 (1)

Will be of the form 4x+3y+k=0.

Since, (-1,3) is a point on it, 4(-1)+3(3)+k=0

Therefore k = -5

Substituting in the equation above, the equation of the straight line passing through(-1,3) and perpendicular to the equation 3x-4y=16 is

4x+3y-5=0 …(2)

Solving equation (1) and equation (2)

4x+3y=5

3x-4y=16

Therefore the foot of the perpendicular is = ()