document.write( "Question 987447: a total of 30,000 is deposited, with equal amounts in 5% and 7% accounts and the balance in a 9% account. After two years, the total interest is 4,920. How much was deposited into each account? \n" ); document.write( "

Algebra.Com's Answer #608240 by macston(5194) $\"\"$ $\"About$

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\n" ); document.write( "F=x=amount in 5% account; S=x=amount in 7% account; N=amount in 9% account
\n" ); document.write( ".
\n" ); document.write( "F+S+N=30000
\n" ); document.write( "x+x+N=30000
\n" ); document.write( "N=30000-2x
\n" ); document.write( ".
\n" ); document.write( "Interest per year=4920/2=2460
\n" ); document.write( ".
\n" ); document.write( "0.05F+0.07S+0.09N=2460
\n" ); document.write( "0.05x+0.07x+0.09(30000-2x)=2460
\n" ); document.write( "0.12x+2700-0.18x=2460
\n" ); document.write( "-0.06x=-240
\n" ); document.write( "x=4000
\n" ); document.write( "F=x=4000 ANSWER 1: 4000 was invested at 5%.
\n" ); document.write( "S=x=4000 ANSWER 2: 4000 was invested at 7%.
\n" ); document.write( "N=30000-2x=22000 ANSWER 3: 22000 was invested at 9%.
\n" ); document.write( ".
\n" ); document.write( "CHECK:
\n" ); document.write( "0.05F+0.07S+0.09N=2460
\n" ); document.write( "0.05(4000)+0.07(4000)+0.09(22000)=2460
\n" ); document.write( "200+280+1980=2460
\n" ); document.write( "2460=2460 \n" ); document.write( "

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