a 6' person is standing x feet away form a 10' lamppost. what is the distance d from the base of the lamppost to the end of the person's shadow, expressed as a function of x

Answer 1

Make a sketch and notice the similar triangles.

by ratio:
d/10 = (d-x)/6
6d = 10d - 10x
-4d = -10x
d = (5/2)x