document.write( "Question 354768: To buy both a new car and a new house, Tina sought two loans totalling $78,825. The simple interest rate on the first loan was 0.2%, while the simple interest rate on the second loan was 5.0%. At the end of the first year, Tina paid a combined interest payment of $2817.23. What were the amounts of the two loans?\r
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document.write( "So far I have this but don't know where to go from there:
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document.write( "x + y = 78,825
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document.write( "0.02x + 0.05y = 2817.23 \n" );
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Algebra.Com's Answer #253468 by solver91311(24713)![]() ![]() You can put this solution on YOUR website! \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Typo or error? Your problem statement says the first loan is at 0.2% simple interest, which really looks like a typo, but if 0.2% is actually correct, then your second equation has an error and should be: \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Either way, there are three basic ways to go about solving your system:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1. Substitution:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Solve \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now substitute into the 2nd equation. (I'm going to go with my gut feeling and say you had a typo in the problem statement, but you can make the adjustment if necessary)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "And then just solve for \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2. Elimination:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Multiply your second equation by -50:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Then add the two equations:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Notice that \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3. Cramer's Rule:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Create the coefficient matrix of your system:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "And then calculate the determinant, \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The determinant\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So you will have\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Then replace the first column of your matrix with the constant values from your equations:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "and then using the same process, calculate the determinant, \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Next, replace the second column:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "From which you calculate \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Finally,\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "and\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "John \n" ); document.write( " \n" ); document.write( "My calculator said it, I believe it, that settles it \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " |