SOLUTION: Beth is planning on investing her $12,000 bonus, putting some in an account earning 7% and the rest in an account earning 5%. How much should she put in each account to have a tota

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Question 980084: Beth is planning on investing her $12,000 bonus, putting some in an account earning 7% and the rest in an account earning 5%. How much should she put in each account to have a total of $760 interest.
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
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S=amount at 7%; F=amount at 5%
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S+F=$12000
S=$12000-F Use this to substitute for S below.
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0.07S+0.05F=$760 Substitute for S from above.
0.07($12000-F)+0.05F=$760
$840-0.07F+0.05F=$760 Subtract $840 from each side.
-0.02F=-$80 Divide each side by -0.02
F=$4000 ANSWER 1: She should invest $4000 in the 5% account.
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S=$12000-$4000
S=$8000 ANSWER 2: She should invest $8000 in the 7% account.
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CHECK:
0.07S+0.05F=$760
0.07($8000)+0.05($4000)=$760
$560+$200=$760
$760=$760