<PRE><B>Question 252427</B>
total investment = $40,000
x is invested at 2% per year.
2x is invested at 4.5% per year.
40000 - 3x is invested at 1.25% per year.  this represents the rest of the money.
825 is total interest after 1 year.


the formula is:


.02*x + .025*2*x + .0125*(40000-3*x) = 825


simplify by removing parentheses to get:


.02*x + .025*2*x + .0125*40000 - .0125*3*x = 825


simplify further by performing indicated operations to get:


.02*x + .05*x + 500 - .0375*x = 825


simplify further by combining like terms to get:


.0325*x + 500 = 825


subtract 500 from both sides of the equation to get:


.0325*x = 825 - 500 = 325


divide both sides of the equation to get:


x = 325/.0325 = 10,000


2x = 20,000


40,000 - 3x = 40,000 - 30,000 = 10,000


she invested $10,000 at 2% to get $200.00
she invested $20,000 at 2.5% to get $500.00
she invested $10,000 at 1.25% to get $125.00


total interest earned is $200.00 + $500.00 + $125.00 = $825.00 confirming these answers are good.


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