document.write( "Question 185848: Dave Salcedo has $40,000 to invest. He invests part of it at 5%, one-fourth of this amount at 6%, and the rest of the money at 7%. His total annual interest income is $2530. Find the amount invested at each rate. \n" ); document.write( "
Algebra.Com's Answer #139434 by ankor@dixie-net.com(22740)\"\" \"About 
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Dave Salcedo has $40,000 to invest. He invests part of it at 5%, one-fourth
\n" ); document.write( " of this amount at 6%, and the rest of the money at 7%. His total annual
\n" ); document.write( " interest income is $2530. Find the amount invested at each rate.
\n" ); document.write( ":
\n" ); document.write( "We have 3 amts
\n" ); document.write( "let x = amt invested at 5%
\n" ); document.write( "then
\n" ); document.write( ".25x = amt invested at 6%
\n" ); document.write( "and
\n" ); document.write( "(40000-1.25x) = amt invested at 7%
\n" ); document.write( ":
\n" ); document.write( ".05x + .06(.25x) + .07(40000-1.25x) = 2530
\n" ); document.write( ":
\n" ); document.write( ".05x + .015x + 2800 - .0875x = 2530
\n" ); document.write( ":
\n" ); document.write( ".05x + .015x - .0875x = 2530 - 2800
\n" ); document.write( ":
\n" ); document.write( "-.0225x = -270
\n" ); document.write( "x = \"%28-270%29%2F%28-.0225%29\"
\n" ); document.write( "x = $12000 invested at 5%
\n" ); document.write( ":
\n" ); document.write( ".25(12000) = $3000 invested at 6%
\n" ); document.write( "and
\n" ); document.write( "40000 - 12000 - 3000 = $25000 invested at 7%
\n" ); document.write( ":
\n" ); document.write( ";
\n" ); document.write( "Check solution by finding the total interest
\n" ); document.write( ".05(12000) + .06(3000) + .07(25000) =
\n" ); document.write( "600 + 180 + 1750 = 2530, confirms out solutions \n" ); document.write( "
\n" );