document.write( "Question 491286: a businessman invested Php. 16,000.000, part at 9% and the rest at 4%. His total interest from both investments was Php. 990.00. How much did he invest at each rate?
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Algebra.Com's Answer #334568 by mananth(16946)\"\" \"About 
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Investment I 9.00% per annum ---x
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\n" ); document.write( "x + y= 16000000 ------------------------1
\n" ); document.write( "9.00% x + 4.00% y = 990000
\n" ); document.write( "Multiply by 100
\n" ); document.write( "9 x + 4 y = 99000000--------2
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\n" ); document.write( "Multiply (1) by -9
\n" ); document.write( "we get
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\n" ); document.write( "-9 x -9 y = -144000000.00
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\n" ); document.write( "Add this to (2)
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\n" ); document.write( "0 x -5 y = -45000000
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\n" ); document.write( "divide by -5
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\n" ); document.write( "y = 9000000 investment at 4.00%
\n" ); document.write( "Balance 7000000 investment at 9.00%\r
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\n" ); document.write( "\n" ); document.write( "CHECK
\n" ); document.write( "7000000 630000.00
\n" ); document.write( "9000000 360000.00
\n" ); document.write( "Total 990000.00
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