Question 138200
using matrix calculations the question is as follows
A total of $ 50,000 is invested in three funds paying 6%,8%, and 10% simple interest. The yearly interest is $3700.00. Twice as much money is invested at 6% as invested at 10%. How much is invested in each of the funds. 
My professor wants us to accomplish the following items. 
a. set up the 3 linear equations in 3 variables
Quantity Eq.: 
x   +  y  +  z    = 50,000
Interest equation:
0.06x + 0.08y  0.10z = 3700
Relation equation:
x = 2z
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Rearrange equations:
x     +  y   +  z    = 50,000
0.06x + 0.08y  0.10z = 3700
x     +  0     -2z   = 0
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Solution got by using Matrix function on TI calculator:
x = 30000
y = 5000
z = 15000
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Cheers,
Stan H.

b. put the coeficients into a matrix
c. solve the matrix any method you like
d. provide the solution for x,y, and z.