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) You can put this solution on YOUR website! 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 = \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 = \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 = \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 \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |