document.write( "Question 1108965: The annual interest on a $19,000 investment exceeds the interest earned on a $5000 investment by $617. The $19,000 is invested at a 0.3% higher rate of interest than the $5000. What is the interest rate of each investment? \n" ); document.write( "
Algebra.Com's Answer #724013 by Theo(13342)![]() ![]() You can put this solution on YOUR website! let x = the interest rate on the 19000 dollar investment.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let y = the interest rate on the 5000 dollar investment.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you get 19000 * x - 5000 * y = 617\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that means that the annual interest on the 19000 dollar investment is 617 dollars higher than the annual interest on the 5000 dollar investment.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you are given that the interest rate on the 19000 dollar investment is .3% higher than the interest rate on the 5000 dollar investment.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( ".3% is equal to .003.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this results in x = y + .003\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you have 2 equations that need to be solved simultaneously.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "they are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "19000 * x - 5000 * y = 617 \n" ); document.write( "x = y + .003\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "replace x in the first equation with the equivalent value of y + .003 from the second equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "19000 * (y + .003) - 5000 * y = 617\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get 19000 * y + 57 - 5000 * y = 617.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "combine like terms to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "14000 * y + 57 = 617.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "subtract 57 from both sides to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "14000 * y = 560.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for y to get y = 560 / 14000 = .04.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you have y = .04 and x = .043, since x is .003 more than .04.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "go back to your original problem to see if it makes sense when x = .043 and y = .04\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the original problem says that the difference between the interest on the 19000 dollar investment and the interest on the 5000 dollar investment is 617 dollars.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the original problem also states that the interest rate on the 19000 dollar investment is .3% higher than the interest rate on the 5000 dollar investment.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "19000 * .043 - 5000 * .04 is equal to 617 dollars, confirming the solution is correct.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the solution is that the interest rate on the 19000 investment is 4.3% and the interest rate on the 5000 dollar investment is 4.0%.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "note that .3% = .003\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the percent rate divided by 100 equal the rate.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |