document.write( "Question 901328: if $8000 is invested in a bank that pays 4% interest, how much more must be invested in bonds at 9% to earn 5% on the total investment? \n" ); document.write( "

Algebra.Com's Answer #546682 by richwmiller(17219) $\"\"$ $\"About$

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x+y=8000
\n" ); document.write( ".04x+.09y=.05(8000)
\n" ); document.write( ".04x+.09y=400
\n" ); document.write( "x=8000-y
\n" ); document.write( "0.04*(8000-y)+0.09*y=400
\n" ); document.write( "320-0.04y+0.09*y=400
\n" ); document.write( "0.05*y=80
\n" ); document.write( "y=1600 at 9%
\n" ); document.write( "x=8000-y
\n" ); document.write( "x=6400 at 4%
\n" ); document.write( "check
\n" ); document.write( "0.04*6400+0.09*1600=400
\n" ); document.write( "256+144=400
\n" ); document.write( "400=400
\n" ); document.write( "ok
\n" ); document.write( " \n" ); document.write( "

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