document.write( "Question 553488: Brian invested $8000, part in a 5% account and the rest in a 10% account. If his annual interest was $ 650. How much did he invest at each rate? \n" ); document.write( "

Algebra.Com's Answer #360879 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+a+\"$ = amount invested @ 5%
\n" ); document.write( "Let $\"+b+\"$ = amount invested @ 10%
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+a+%2B+b+=+8000+\"$
\n" ); document.write( "(2) $\"+.05a+%2B+.1b+=+650+\"$
\n" ); document.write( "---------------------
\n" ); document.write( "(2) $\"+5a+%2B+10b+=+65000+\"$
\n" ); document.write( "Multiply both sides of (1) by $\"+5+\"$
\n" ); document.write( "and subtract (1) from (2)
\n" ); document.write( "(2) $\"+5a+%2B+10b+=+65000+\"$
\n" ); document.write( "(1) $\"+-5a+-+5b+=+40000+\"$
\n" ); document.write( " $\"+5b+=+25000+\"$
\n" ); document.write( " $\"+b+=+5000+\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+a+%2B+b+=+8000+\"$
\n" ); document.write( "(1) $\"+a+%2B+5000+=+8000+\"$
\n" ); document.write( "(1) $\"+a+=+3000+\"$
\n" ); document.write( "He invested $3,000 @ 5% and
\n" ); document.write( "$5,000 @ 10%
\n" ); document.write( "check answer:
\n" ); document.write( "(2) $\"+.05a+%2B+.1b+=+650+\"$
\n" ); document.write( "(2) $\"+.05%2A3000+%2B+.1%2A5000+=+650+\"$
\n" ); document.write( "(2) $\"+150+%2B+500+=+650+\"$
\n" ); document.write( "(2) $\"+650+=+650+\"$
\n" ); document.write( "OK \n" ); document.write( "

\n" );