SOLUTION: A man invests $1800 in three accounts that pay 5%, 7% and 9% in annual interest respectively. He has 3 times as much invested at 9% as he does at 5%. If his total interest for the
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Question 930237: A man invests $1800 in three accounts that pay 5%, 7% and 9% in annual interest respectively. He has 3 times as much invested at 9% as he does at 5%. If his total interest for the year is $138 , how much is invested at each rate?
You can put this solution on YOUR website! x = amount at 5%
y = amount at 7%
z = amount at 9%
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x + y + z = 1800
z = 3x
0.05x + 0.07y + 0.09z = 138
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put the system of linear equations into standard form
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x + y + z = 1800
3x - z = 0
0.05x + 0.07y + 0.09z = 138
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copy and paste the above standard form linear equations in to this solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
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solution:
x = amount at 5% = 300
y = amount at 7% = 600
z = amount at 9% = 900
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