document.write( "Question 659057: Paul and Donna Petrie invested $12,000 part at 5% simple interest and the rest a 7% simple interest for a period of 1 year. How much did they invest at each rate if their total annual interest from both investments was $800? (Use interest= principal x rate x time.) \n" ); document.write( "

Algebra.Com's Answer #410616 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
interest= principal x rate x time
\n" ); document.write( "Let $\"+x+\"$ = amount invested at 5%
\n" ); document.write( " $\"+12000+-+x+\"$ = amount invested at 7%
\n" ); document.write( " $\"+I%5B1%5D+=+x%2A.05%2A1+\"$
\n" ); document.write( " $\"+I%5B1%5D+=+.05x+\"$
\n" ); document.write( "--------------
\n" ); document.write( " $\"+I%5B2%5D+=+%28+12000+-+x+%29%2A.07%2A1+\"$
\n" ); document.write( " $\"+I%5B2%5D+=+840+-+.07x+\"$
\n" ); document.write( "-------------------
\n" ); document.write( " $\"+I%5B1%5D+%2B+I%5B2%5D+=+800+\"$
\n" ); document.write( " $\"+.05x+%2B+840+-+.07x+=+800+\"$
\n" ); document.write( " $\"+-.02x+=+-40+\"$
\n" ); document.write( " $\"+x+=+2000+\"$
\n" ); document.write( " $\"+12000+-+x+=+12000+-+2000+\"$
\n" ); document.write( " $\"+12000+-+x+=+10000+\"$
\n" ); document.write( "$2,000 = amount invested at 5%
\n" ); document.write( "$10,000 = amount invested at 7%
\n" ); document.write( " \n" ); document.write( "

\n" );