Answer: 4,170
Step-by-step explanation:

She would pay $132 for the chandelier
Answer:
A, but that isn't really the most mathmatical way to put it, and it might not apply to other equations.
P(t)=500(1+4t/(50+t^2 ))
P'(t) = 500 [(50+t^2).4 - 4t.2t]/(50+t^2)^2
by the quotient rule
500 (-4t^2 + 200)/(t^2 + 50)^2
Hence
P'(2) = 500 . (-16 + 200)/54^2 ~= 31.6