document.write( "Question 373434: $9500 is invested, part of it at 10% and part of it at 8%. For a certain year, the total yield is $878.00. How much was invested at each rate?\r
\n" ); document.write( "\n" ); document.write( "How much was invested at 10%? \r
\n" ); document.write( "\n" ); document.write( "How much was invested at 8%? \n" ); document.write( "

Algebra.Com's Answer #265786 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"a\"$ = amount invested at 10%
\n" ); document.write( "Let $\"b\"$ = amount invested at 8%
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"a+%2B+b+=+9500\"$
\n" ); document.write( " $\".1a+%2B+.08b+=+878\"$
\n" ); document.write( "(2) $\"10a+%2B+8b+=+87800\"$
\n" ); document.write( "Multiply both sides of (1) by $\"8\"$
\n" ); document.write( "and subtract (1) from (2)
\n" ); document.write( "(2) $\"10a+%2B+8b+=+87800\"$
\n" ); document.write( "(1) $\"-8a+-+8b+=+-76000\"$
\n" ); document.write( " $\"2a+=+11800\"$
\n" ); document.write( " $\"a+=+5900\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"5900+%2B+b+=+9500\"$
\n" ); document.write( " $\"b+=+3600\"$
\n" ); document.write( "$5,900 was invested at 10% and $3,600 was invested at 8%
\n" ); document.write( "check answer:
\n" ); document.write( " $\".1a+%2B+.08b+=+878\"$
\n" ); document.write( " $\".1%2A5900+%2B+.08%2A3600+=+878\"$
\n" ); document.write( " $\"590+%2B+288+=+878\"$
\n" ); document.write( " $\"878+=+878\"$
\n" ); document.write( "OK \n" ); document.write( "

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