SOLUTION: tamara invested 8000 in two different accounts. The first account has a simple interest rate of 3% and the second account has a simple interest rate of 4%. If the firs account earn

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Question 908912: tamara invested 8000 in two different accounts. The first account has a simple interest rate of 3% and the second account has a simple interest rate of 4%. If the firs account earns $37 more interest than the second account at the end of one year, how much did she invest in each account?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
We know the total amount of money invested. $8000
x+y=8000,
We know that the difference in interest earned by the two accounts is $37
0.03*x-0.04*y=37
x=8000-y
We substitute for x
0.03*(8000-y)-0.04*y=37
We multiply out
240-0.03y-0.04*y=37
We combine like terms.
203=0.07*y
Isolate y
y=203/0.07
y=2900 at 4%
Calculate x
x=8000-2900
x=5100 at 3%
Interest earned at 3% is 153
Interest earned at 4% is 116
We check
0.03*5100-0.04*2900=37
153-116=37
37=37
Since this statement is TRUE and neither x nor y is negative then all is well