document.write( "Question 221206: You are going to invest $25,000, part at 14% and part at 16%. What is the most that can be invested at 14% in order to make at least $3000 interest per year? \n" ); document.write( "
Algebra.Com's Answer #165962 by RAY100(1637)![]() ![]() ![]() You can put this solution on YOUR website! Let x = amt at 14% and y = amt at 16% \n" ); document.write( ". \n" ); document.write( ".14x +.16y = $ 3000 \n" ); document.write( ". \n" ); document.write( "but,,,x+y=$ 25,000,,,,,,,or y=25,000 -x,,,,,subst \n" ); document.write( ". \n" ); document.write( ".14x + .16(25,000-x) = 3000 \n" ); document.write( ". \n" ); document.write( ".14x + 4,000 - .16x = 3000 \n" ); document.write( ". \n" ); document.write( "- .02 x = -1000 \n" ); document.write( ". \n" ); document.write( "x= $ 50,000,,,,,y= - $ 25,000 \n" ); document.write( ". \n" ); document.write( "Checking,,, 50000(.14) - 25000(.16) = 7000 - 4000 = 3000,,,math correct BUT \n" ); document.write( ". \n" ); document.write( ", \n" ); document.write( "To make $ 3000 from $ 25,000,, need return of 3000/25000= .12 or 12 % ,,,only \n" ); document.write( ". \n" ); document.write( ". \n" ); document.write( "The real question is how much at 14 % = $ 30,000 \n" ); document.write( ". \n" ); document.write( ".14 * x = $3000,,,,x= 3000/ .14 = $ 21,428.57 \n" ); document.write( ". \n" ); document.write( ". \n" ); document.write( ". \n" ); document.write( "If we invested all at 16%, we would invest,,,y= 3000/.16 = $ 18,750 \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( " |