Well, without even looking at it, I can say it's a downwards facing parabola, which roots at x = -3 and x = 5. That should do it.
Answer:
A = P(1+r÷100)^n
where A is amount after some days
r is the rate
n is the number of years
p is the principle (the amount of money before the interest)
A = 5000 ( 1 + 12÷100)^5
A = 8811.70
A = 8812
-4 1/2, -2 3/8, 1.35, 5.6