document.write( "Question 258029: Janet invested $27,000, part at 15% and part at 9%. If the total interest at the end of the year is $3,390, how much did she invest at 15%? \n" ); document.write( "

Algebra.Com's Answer #189879 by drk(1908) $\"\"$ $\"About$

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This question is modeled after the I = prt question. IN this case however, we have two investments. So we can write
\n" ); document.write( "I = prt + prt
\n" ); document.write( "based on the given information, we get
\n" ); document.write( "(i) $\"3390+=+x%28.15%29%281%29+%2B+%2827000-x%29%28.09%29%281%29\"$
\n" ); document.write( "simplifying (i) , we get
\n" ); document.write( "(ii) $\"3390+=+.15x+%2B+2430+-.09x\"$
\n" ); document.write( "and then
\n" ); document.write( "(iii) $\"3390+=+.06x+%2B+2430\"$
\n" ); document.write( "subtracting, we get
\n" ); document.write( "(iv) $\"1060+=+.06x\"$
\n" ); document.write( "and dividing, we get
\n" ); document.write( "x = $11,777.78 @ 15%
\n" ); document.write( "and
\n" ); document.write( "27000 - x = $15,222.22 @ 9%.
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