The equation for line r is
y=-1/3x+5
Perpendicular slope would be 3 and passes through (3,-6)
-6=3(3)+b
-6=9+b
-9. -9
-15=b
y=3x-15
Plug in the x value of the point to see if it’s true
y=3(3)-15
y=9-15
y=-6
So the equation is y=3x-15 so the answers is c
3x-y=15
-3x. -3x
-y=-3x+15
Divide everything by -1
y=3x-15