document.write( "Question 79794This question is from textbook Elementary and intermediate algebra
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document.write( ": Jane invested some amount at the rate of 12% simple interest and some other amount at the rate of 10% simple interest. She received yearly interest of $130. Randy also invested in the same scheme, but he interchanged the amounts invested, and received $4. more as interest. How much amount did each of them invest at different rates
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Algebra.Com's Answer #57290 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! Jane invested some amount at the rate of 12% simple interest and some other amount at the rate of 10% simple interest. She received yearly interest of $130. Randy also invested in the same scheme, but he interchanged the amounts invested, and received $4. more as interest. How much amount did each of them invest at different rates. \n" ); document.write( ": \n" ); document.write( "Let x = amt J invested at 12% \n" ); document.write( "Let y = amt J invested at 10% \n" ); document.write( ": \n" ); document.write( "Randy interchanged the amts so: \n" ); document.write( "x = amt R invested at 10% \n" ); document.write( "y = amt R invested at 12% \n" ); document.write( ": \n" ); document.write( ".12x + .10y = 130; J's earnings \n" ); document.write( ".10x + .12y = 134; R's earnings \n" ); document.write( ": \n" ); document.write( " Multiply 1st equation by 120 and 2nd equation by 100: \n" ); document.write( "14.4x + 12y = 15600 \n" ); document.write( " 10x + 12y = 13400 \n" ); document.write( "--------------------- subtracting eliminates y \n" ); document.write( " 4.4x + 0 = 2200 \n" ); document.write( "x = 2200/4.4 \n" ); document.write( "x = $500 invested at 12% by J, $500 invested at 10% by R \n" ); document.write( ": \n" ); document.write( "Find y: \n" ); document.write( ".12(500) + .10y = 130 \n" ); document.write( " 60 + .1y = 130 \n" ); document.write( ".1y = 130 - 60 \n" ); document.write( "y = 70/.1 \n" ); document.write( "y = $700 invested at 10% by J, $700 invested at 12% by R \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check our solutions using; .10x + .12y = 134: \n" ); document.write( ".1(500) + .12(700) = \n" ); document.write( " 50 + 84 = 134 \n" ); document.write( ": \n" ); document.write( "Make sense to you? Hope so. \n" ); document.write( " \n" ); document.write( " |