document.write( "Question 52217: bob invested $20,00, part at 14% and part at 13%. If the total interest at the end of the year is $2,720, how much did he invest at 14%? \n" ); document.write( "
Algebra.Com's Answer #34787 by funmath(2933)\"\" \"About 
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(interest)=(principle)(rate)(time) or i=prt, in this case t is 1, so i=pr.
\n" ); document.write( "The amount of principle (p)invested at 14%: x
\n" ); document.write( "Let the rest of the $20,000 be the principle (p)invested at 13%:20,000-x
\n" ); document.write( "rate (r) at 14%=14/100=.14
\n" ); document.write( "rate (r) at 13%=13/100=.13
\n" ); document.write( "Therefore the interest earned at 14% is: .14x
\n" ); document.write( "and the interest earned at 13% is: .13(20,000-x)
\n" ); document.write( "If you add the two interests together and you get:$2,720
\n" ); document.write( "So your equation is:
\n" ); document.write( ".14x+.13(20,000-x)=2,720 Sometimes it makes easier to eliminate the decimals by multiplying both sides of the equation by 100.
\n" ); document.write( "100(.14x+.13(20,000-x))=100(2,720)
\n" ); document.write( "100(.14)x+100(.13)(20,000-x)=100(2,720)
\n" ); document.write( "14x+13(20,000-x)=272,000
\n" ); document.write( "14x+13(20,000)-13(x)=272,000
\n" ); document.write( "14x+260,000-13x=272,000
\n" ); document.write( "(14-13)x+260,000=272,000
\n" ); document.write( "x+260,000-260,000=272,000-260,000
\n" ); document.write( "x=12,000
\n" ); document.write( "The amount of money invested at 14% is $12,000. \n" ); document.write( "
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