document.write( "Question 514594: A man has 3 sums of money invested, one at 12%, one at 10% and the last at 8%, his total annual income from the three investments is 2100 the first investment yields as much as the other 2 combined, if he could receive 1% more on each investments his annual income would be increased by 202.50. How much is his investments at each rate? \n" ); document.write( "
Algebra.Com's Answer #343580 by ankor@dixie-net.com(22740)\"\" \"About 
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A man has 3 sums of money invested, one at 12%, one at 10% and the last at 8%,
\n" ); document.write( " his total annual income from the three investments is 2100
\n" ); document.write( " the first investment yields as much as the other 2 combined, \"
\n" ); document.write( "How much is his investments at each
\n" ); document.write( ":
\n" ); document.write( "Write an equation for each statement:
\n" ); document.write( ";
\n" ); document.write( "\"A man has 3 sums of money invested, one at 12%, one at 10% and the last at 8%,
\n" ); document.write( " his total annual income from the three investments is 2100\"
\n" ); document.write( ".12x + .10y + .08z = 2100
\n" ); document.write( ":
\n" ); document.write( "\"the first investment yields as much as the other 2 combined, \"
\n" ); document.write( ".12x = .10y + .08z
\n" ); document.write( "rewrite this to
\n" ); document.write( ".12x - .10y - .08z = 0
\n" ); document.write( ":
\n" ); document.write( "\"if he could receive 1% more on each investments his annual income would be increased by 202.50\"
\n" ); document.write( ".13x + .11y + .09z = 202.50 + 2100
\n" ); document.write( ".13x + .11y + .09z = 2302.50
\n" ); document.write( ":
\n" ); document.write( "Add these two equation
\n" ); document.write( ".12x + .10y + .08z = 2100
\n" ); document.write( ".12x - .10y - .08z = 0
\n" ); document.write( "------------------------addition eliminates y and z, find x
\n" ); document.write( ".24x = 2100
\n" ); document.write( "x = \"2100%2F.24\"
\n" ); document.write( "x = $8,750 invested at 12%
\n" ); document.write( ":
\n" ); document.write( "Find the return on this amt
\n" ); document.write( ".12(8750) = $1050
\n" ); document.write( ":
\n" ); document.write( "\"the first investment yields as much as the other 2 combined, \"
\n" ); document.write( ".10y + .08z = 1050
\n" ); document.write( ":
\n" ); document.write( "\"receive 1% more on each investments his annual income would be increased by 202.50\"
\n" ); document.write( ".01(8750) + .01y + .01z = 202.50
\n" ); document.write( "87.50 + .01y + .01z = 202.50
\n" ); document.write( ".01y + .01z = 202.50 - 87.50
\n" ); document.write( ".01y + .01z = 115
\n" ); document.write( "multiply by 10, subtract the previous equation
\n" ); document.write( ".10y + .10z = 1150
\n" ); document.write( ".10y + .08z = 1050
\n" ); document.write( "--------------------subtraction eliminates y, find z
\n" ); document.write( ".02z = 100
\n" ); document.write( "z = \"100%2F.02\"
\n" ); document.write( "z = $5000 invested at 8%
\n" ); document.write( ":
\n" ); document.write( "Use equation: .01y + .01z = 115, to find y, replace z
\n" ); document.write( ".01y + .01(5000) = 115
\n" ); document.write( ".01y + 50 = 115
\n" ); document.write( ".01y = 115 - 50
\n" ); document.write( ".01y = 65
\n" ); document.write( "y = \"65%2F.01\"
\n" ); document.write( "y = $6500 invested at 10%
\n" ); document.write( ":
\n" ); document.write( "Summarize:
\n" ); document.write( "x = $8750 invested at 12%
\n" ); document.write( "y = $6500 invested at 10%
\n" ); document.write( "z = $5000 invested at 8%
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check this by finding the total return using these values
\n" ); document.write( ".12(8750) + .10y(6500)+ .08(5000) =
\n" ); document.write( "1050 + 650 + 400 = 2100, confirms our solutions\r
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