document.write( "Question 231809: Robert invests $8000 in a bank. Part is invested at 7% simple interest and part at 9% simple interest. In one year Robert earns $660 in interest. How much did he invest at each amount? \n" ); document.write( "
Algebra.Com's Answer #171476 by rfer(16322)\"\" \"About 
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.07x+.09(8000-x)=660
\n" ); document.write( ".07x+720-.09x=660
\n" ); document.write( "-.02x=-60
\n" ); document.write( "x=$3000 at 7%
\n" ); document.write( "$5000 at 9%
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