What is the simple interest rate on an account that earned $56.25 in interest after two and one-half years on a principal balance of $300 Plz show work

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50

- both graphs increase on their domain.

- the graphs of both functions have the same x-intercept.

- neither graph has a y-intercept.

i think the answer is d im not sure