document.write( "Question 1099466: An executive invests $27,000, some at 7% and the rest at 5% annual interest. If he receives an annual return of $1,710, how much is invested at each rate? \n" ); document.write( "

Algebra.Com's Answer #713886 by ikleyn(52852) $\"\"$ $\"About$

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

\r\n" );
document.write( "Let x be the amount invested at 7% (in dollars).\r\n" );
document.write( "\r\n" );
document.write( "Then the amount invested at 5% is (27000-x) dollars.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Then the equation for the \"earned interest\" is\r\n" );
document.write( "\r\n" );
document.write( "0.07x + 0.05(27000-x) = 1710.     (<<<---===  earning from two investments)\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "It is your basic equation.\r\n" );
document.write( "As soon as you got it, the setup is done.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "To solve the equation, multiply both sides by 100. You will get\r\n" );
document.write( "\r\n" );
document.write( "7x + 5*(27000-x) = 171000  ====>  \r\n" );
document.write( "\r\n" );
document.write( "7x + 135000 - 5x = 171000  ====>  2x = 171000-135000 = 36000  ====>  x =  = 18000.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Answer. $18000 invested at 7%,  the rest 27000-18000 = 9000 was invested at 5%.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Check.  0.07*18000 + 0.05*9000 = 1710.   ! Correct !\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( "------------
\n" ); document.write( "To see more similar solved problems on investments, look into the lessons\r
\n" ); document.write( "\n" ); document.write( " - Using systems of equations to solve problems on investment\r
\n" ); document.write( "\n" ); document.write( "in this site.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );