document.write( "Question 260828: Part of 8,000 was invested at 10% and the rest at 12%. If the annual income from these investments was 860.00 how much was invested at each rate. I need help with this one.Each rate meaning 10% and 12 % \n" ); document.write( "
Algebra.Com's Answer #192127 by Theo(13342)\"\" \"About 
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total invested is 8,000\r
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\n" ); document.write( "\n" ); document.write( "let x be one part.
\n" ); document.write( "let y be the other part.\r
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\n" ); document.write( "\n" ); document.write( "you have x + y = 8000 (equation 1)\r
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\n" ); document.write( "\n" ); document.write( "total annual income is 860.000\r
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\n" ); document.write( "\n" ); document.write( "x part is invested at 10%
\n" ); document.write( "y part is invested at 12%\r
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\n" ); document.write( "\n" ); document.write( "you have .10*x + .12*y = 860 (equation 2)\r
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\n" ); document.write( "\n" ); document.write( "you need to solve these 2 equations simultaneously.\r
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\n" ); document.write( "\n" ); document.write( "solve for y in equation 1 to get y = 8000 - x\r
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\n" ); document.write( "\n" ); document.write( "substitute for y in equation 2 to get .10*x + .12*(8000-x) = 860\r
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\n" ); document.write( "\n" ); document.write( "solve for x in equation 2.\r
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\n" ); document.write( "\n" ); document.write( "equation is:\r
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\n" ); document.write( "\n" ); document.write( ".10*x + .12*(8000-x) = 860\r
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\n" ); document.write( "\n" ); document.write( "simplify to get:\r
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\n" ); document.write( "\n" ); document.write( ".10*x + .12*8000 - .12*x = 860\r
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\n" ); document.write( "\n" ); document.write( "simplify to get:\r
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\n" ); document.write( "\n" ); document.write( "-.02*x + 960 = 860\r
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\n" ); document.write( "\n" ); document.write( "subtract 960 from both sides of this equation to get:\r
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\n" ); document.write( "\n" ); document.write( "-.02*x = -100\r
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\n" ); document.write( "\n" ); document.write( "divide both sides of this equation by -.02 to get:\r
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\n" ); document.write( "\n" ); document.write( "x = 5000\r
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\n" ); document.write( "\n" ); document.write( "that means y = 3000 because x + y = 8000.\r
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\n" ); document.write( "\n" ); document.write( "you have x = 5000 and y = 3000.\r
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\n" ); document.write( "\n" ); document.write( "substitute in equation 2 to get:\r
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\n" ); document.write( "\n" ); document.write( ".10*5000 + .12*3000 = 860\r
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\n" ); document.write( "\n" ); document.write( "simplify to get:\r
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\n" ); document.write( "\n" ); document.write( "500 + 360 = 860 which is true confirming the values for x and y are good.\r
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\n" ); document.write( "\n" ); document.write( "your answer is:\r
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\n" ); document.write( "\n" ); document.write( "$5000 was invested at 10% and $3000 was invested at 12%.\r
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