Mary has a total of $5000 invested in two accounts. One account pays 5% and the other 8%. Her interest in the first year was $331. Write and solve a system of equations to find out how much she has invested in both accounts.

Question

Mary has a total of $5000 invested in two accounts.  One account pays 5% and the other 8%.  Her interest in the first year was $331.  Write and solve a system of equations to find out how much she has invested in both accounts.

Reiny · Answer

amount invested at 5% --- x
amount invested at 8% --- y

x+y = 5000
(5/100)x + (8/100)y = 331
times 100
5x + 8y = 33100
first equation times 5
5x + 5y = 25000
subtract them:
3y = 8100
y = 2700
take over....

jenna · Answer

2300