You invested a total of $25000 at 3% and 4.5% simple interest. During one year, the two accounts earned $900. How much did you invest in each account?

A:amount of money invested in the account with 3% simple interest

B: amount of money invested in the account with 4.5% simple interest

a+b=25000 - - >a=25000-b

0.03a+0.045b=900

30a+45b=900000

2a+3b=60000

2 (25000-b) + 3b=60000

50000-2b+3b=60000

B=10000

A=25000-10000=15000