Question 807386
A = P(1 + rt)


A = final amount = $6,500
P = principal (initial) amount = $4000
r = interest rate = 0.07
t = time (in years) = x


6500 = 4000(1 + 0.07x)
1.625 = 1 + 0.07x
0.625 = 0.07x
x = 8.928 years ----> 9 yrs