document.write( "Question 439539: Walt made an extra $9000 last year from a part-time job. He invested part of the money at a 9% annual rate of interest, and the rest at an 8% annual rate of interest. At the end of the year, he made a total of $770 in interest. How much was invested at 8%? \n" ); document.write( "
Algebra.Com's Answer #316506 by jorel1380(3719)\"\" \"About 
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m+n=9000
\n" ); document.write( ".09m+.08n=770
\n" ); document.write( "9m+8n=77000
\n" ); document.write( "8m+8n=72000
\n" ); document.write( "m=5000
\n" ); document.write( "n=4000
\n" ); document.write( "$4000 was invested at 8%..
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