You invested ​$25000 in two accounts paying 8 % and 9 % annual​ interest, respectively. If the total interest earned for the year was $ 2180 how mu

Question

 help me this problem has me stuck

Answer 1

a + b = 25,000 -----> a = 25,000 - b

0.08a + 0.09b = 2180

 

Substitute!

 

0.08(25,000 - b) + 0.09b = 2180

2000 - 0.08b + 0.09b = 2180

0.01b = 180

b = 18,000

 

a = 25,000 - 18,000

a = 7000