document.write( "Question 185477: Solving Problems Using Linear Systems
\n" ); document.write( "4. Rehman invests his summer earnings of $3050. He invests part of the money at 8%/year, and the rest at 7.5%/year. After 1 year, these investments earn $242 in simple interest. How much did he invest at each rate?
\n" ); document.write( "(answers are: $2650 at 8%/year and $400 at 7.5%/year, but i dont know how to solve it?) \n" ); document.write( "

Algebra.Com's Answer #139142 by stanbon(75887) $\"\"$ $\"About$

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Rehman invests his summer earnings of $3050. He invests part of the money at 8%/year, and the rest at 7.5%/year. After 1 year, these investments earn $242 in simple interest. How much did he invest at each rate?
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\n" ); document.write( "Quantity Equation: x + y = 3050 dollars
\n" ); document.write( "Interest Equation:0.08x + 0.076y = 242
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\n" ); document.write( "Modify these equations so you can eliminate one of the variables:
\n" ); document.write( "80x + 80y = 244000
\n" ); document.write( "80x + 76y = 242000
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\n" ); document.write( "4y = 2000
\n" ); document.write( "y = 500 (amt invested at 7.6%
\n" ); document.write( "Substitute into x+y = 2050
\n" ); document.write( "x + 500 = 3050
\n" ); document.write( "x = 2550 (amt invested at 8%)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "

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