83. A finance company offers a client two investment bonds, the first maturing in 1 year, in the amount of R$ 15,000.00, and the second in 1 year and a half, in the amount of R$ 25,000.00. The interest rate considered in the operation was 2.5% per month. What is the amount applied?

$$ A=P\left(1+r\right)^n $$ Now we can calculate the amounts A1 and A2 for each investment: For the first investment: $$ A_1=15000\times\left(1+0.025\right)^{12} $$ For the second investment: $$ A_2=25000\times\left(1+0.025\right)^{18} $$ Calculating these values gives us the final amounts for each investment: $$ A_1\approx19484.2652 $$ $$ A_2\approx32507.5149 $$ So, the amount applied for the first investment is approximately R$ 19,484.27, and the amount applied for the second investment is approximately R$ 32,507.51.