Question 179408
the annual interest rate = r  
$8,000 in a savings account for two years.--> 8000*(1+r)^2
beginning of the second year, an additional $2,500 is invested-->2500*(100+r)
8000*(1+r)^2  +  2500*(1+r)  =  11,445
suppose 100+r = A
8000*A^2  +  2500*A  =  11,445
8000*A^2  +  2500*A  - 11,445  = 0
A = 1.05
r = 0.05 or 5 % Ans.