<PRE><B>Question 129339</B>
Using matrix calculations, solve the following problem. Show Your Work. 
A total of $50,000 is invested in three funds paying 6%, 8%, and 10% simple interest. The yearly interest is $3,700. Twice as much money is invested at 6% as invested at 10%. How much is invested in each of the funds. 

set up the 3 linear equations in 3 variables 
put the coefficients into a matrix 
solve the matrix using any method you like 
provide the solutions for x, y, and z
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Quantity Equation:    x   +   y   +  z  = 50,000
Interest EQUATION:0.06x  + 0.08y  + 0.10z = 3700
Relation Equation:    x  +   0    - 2z     = 0
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Using the Matrix function of a TI calculator I got:
x = 30000
y = 5000
z = 15000
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Cheers,
Stan H. 
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