document.write( "Question 865364: Susan inherited $12,000 and invested some of it in an account earning 5% simple interest and put the rest in an account earning 8% simple interest. If she earned a total of $810 in interest after 1 year, how much did she invest in each account? \n" ); document.write( "
Algebra.Com's Answer #521646 by mananth(16946)![]() ![]() You can put this solution on YOUR website! Part I 5.00% per annum ------------- Amount invested =x \n" ); document.write( "Part II 8.00% per annum ------------ Amount invested = y \n" ); document.write( " 12000 \n" ); document.write( "Interest----- 810.00 \n" ); document.write( " \n" ); document.write( "Part I 5.00% per annum ---x \n" ); document.write( "Part II 8.00% per annum ---y \n" ); document.write( "Total investment \n" ); document.write( "x + 1 y= 12000 -------------1 \n" ); document.write( "Interest on both investments \n" ); document.write( "5.00% x + 8.00% y= 810 \n" ); document.write( "Multiply by 100 \n" ); document.write( "5 x + 8 y= 81000.00 --------2 \n" ); document.write( "Multiply (1) by -5 \n" ); document.write( "we get \n" ); document.write( "-5 x -5 y= -60000.00 \n" ); document.write( "Add this to (2) \n" ); document.write( "0 x 3 y= 21000 \n" ); document.write( "divide by 3 \n" ); document.write( " y = 7000 \n" ); document.write( "Part I 5.00% $ 5000 \n" ); document.write( "Part II 8.00% $ 7000 \n" ); document.write( " \n" ); document.write( "CHECK \n" ); document.write( "5000 --------- 5.00% ------- 250.00 \n" ); document.write( "7000 ------------- 8.00% ------- 560.00 \n" ); document.write( "Total -------------------- 810.00 \n" ); document.write( " \n" ); document.write( "m.ananth@hotmail.ca \n" ); document.write( " \n" ); document.write( " |