document.write( "Question 965166: Carmella Santiago earned 42,000 in book royalties. She invested part at 15% simple interest and the rest at 12%, earning 5,790 per year in interest. How much did she invest at each rate?\r
\n" ); document.write( "\n" ); document.write( "I know you have to use I= prt... Right? I just never know how to write it out... \n" ); document.write( "

Algebra.Com's Answer #589920 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+x+\"$ = amount invested @ 15%
\n" ); document.write( " $\"+42000+-+x+\"$ = amount invested @ 12%
\n" ); document.write( "---------------------
\n" ); document.write( " $\"+I+=+P%2Ar%2At+\"$
\n" ); document.write( "I think they want $\"+t+=+1+\"$ ( 1 year )
\n" ); document.write( "Make this 2 equations:
\n" ); document.write( " $\"+I%5B1%5D+=+P%5B1%5D%2Ar%5B1%5D%2A1+\"$
\n" ); document.write( " $\"+I%5B2%5D+=+P%5B2%5D%2Ar%5B2%5D%2A1+\"$
\n" ); document.write( " $\"+r%5B1%5D+=+15%2F100+\"$
\n" ); document.write( " $\"+r%5B2%5D+=+12%2F100+\"$
\n" ); document.write( "--------------------
\n" ); document.write( "Add the equations
\n" ); document.write( " $\"+I%5B1%5D+%2B+I%5B2%5D+=+x%2A%28+15%2F100+%29+%2B+%28+42000+-+x+%29%2A%28+12%2F100+%29+\"$
\n" ); document.write( " $\"+5790+=+%283%2F20%29%2Ax+%2B+%28+3%2F25+%29%2A%28+42000+-+x+%29+\"$
\n" ); document.write( "Now find $\"+x+\"$ and $\"+42000+-+x+\"$ \r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );