document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1140346>Question 1140346</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A person ivested $6,700 for one year, part at 8%, part at 10%, and the remained at 12%. The total annual income from these investments was $716. The amount of money invested at 12% was $300 more than the amount invested at 8% and 10% combined. Let x is the amount of money invested at 8%, y is the amount of money invest at 10%, and z is the amount of money invested at 12%. \r<BR>\n" );
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document.write( "a. Write the linear system of equations that models the conditions of the problem.\r<BR>\n" );
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document.write( "b. Write the augmented matrix for the system of linear equations<BR>\n" );
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document.write( "The problem tells you the variables to use:<BR>\n" );
document.write( "x = amount at 8%<BR>\n" );
document.write( "y = amount at 10%<BR>\n" );
document.write( "z = amount at 12%<br><BR>\n" );
document.write( "(1) \"A person invested $6,700...\"  -->  x+y+z = 6700<br><BR>\n" );
document.write( "(2) \"The total annual income from these investments was $716.\"  -->  .08x+.10y+.12z = 716<br><BR>\n" );
document.write( "(3) \"The amount of money invested at 12% was $300 more than the amount invested at 8% and 10% combined.\"  -->  z = x+y+300<br><BR>\n" );
document.write( "(a) The three equations are<br><BR>\n" );
document.write( "x+y+z = 6700<BR>\n" );
document.write( ".08x+.10y+.12z = 716<BR>\n" );
document.write( "z = x+y+300<br><BR>\n" );
document.write( "(b) For solving the system using matrices, the equations must be in the form Ax+By+Cz = D.  Two of the three equations are already in that form; you need to do a bit of work on the third one.<br><BR>\n" );
document.write( "Then the augmented matrix is the coefficients of the three equations.... </SPAN>\n" );
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