A car is traveling at night along a highway shaped like a parabola with its vertex at the origin. The car starts at a point 100 m west and 100 m north of the origin and travels inan easterly direction. There is a statue located 100 m east and 50 m north of the origin. At what point on the highway will the car's headlights illuminate the statue?

what i have so far:

y'(x)=m=(50-y)/(100-x)

delta x=100-x

delta y=50-y

delta y=f(x+deltax)-f(x)

=50-y=100-x

y'=1

y=x-50

I dont no how to finish the problem off so and i feel like i am going in circles, so any help would be great! Thanks!!!!