document.write( "Question 149097: Problem: Walt made an extra $9000 last year from a part-time job. He invested part of the money at 9% and the rest at 8% he made a total of $770 in interest. How much was invested at 8%? \n" ); document.write( "

Algebra.Com's Answer #109371 by josmiceli(19441) $\"\"$ $\"About$

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$\"a\"$ = amount invested at 9%
\n" ); document.write( " $\"b\"$ = amount invested at 8%
\n" ); document.write( " $\"a+%2B+b+=+9000\"$ and,
\n" ); document.write( " $\"a+=+9000+-+b\"$
\n" ); document.write( " $\".09a+%2B+.08b+=+770\"$
\n" ); document.write( " $\".09%2A%289000+-+b%29+%2B+.08b+=+770\"$
\n" ); document.write( " $\"810+-+.09b+%2B+.08b+=+770\"$
\n" ); document.write( " $\"-.01b+=+-40\"$
\n" ); document.write( " $\"b+=+4000\"$
\n" ); document.write( "$4,000 was invested at 8%
\n" ); document.write( "check answer:
\n" ); document.write( " $\"a+%2B+b+=+9000\"$
\n" ); document.write( " $\"a+%2B+4000+=+9000\"$
\n" ); document.write( " $\"a+=+5000\"$
\n" ); document.write( " $\".09a+%2B+.08b+=+770\"$
\n" ); document.write( " $\".09%2A5000+%2B+.08%2A4000+=+770\"$
\n" ); document.write( " $\"450+%2B+320+=+770\"$
\n" ); document.write( " $\"770+=+770\"$
\n" ); document.write( "OK \n" ); document.write( "

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