document.write( "Question 133662: if 20lb of rice and 10lb of potatoes cost $16.20, and 30lb of rice and 12lb of potatoes cost $23.04, how much will 10lb of rice and 50lb of potatoes cost? \n" ); document.write( "

Algebra.Com's Answer #97803 by stanbon(75887) $\"\"$ $\"About$

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if 20lb of rice and 10lb of potatoes cost $16.20, and 30lb of rice and 12lb of potatoes cost $23.04, how much will 10lb of rice and 50lb of potatoes cost?
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\n" ); document.write( "Let \"r\" be cost of rice; Let \"p\" be cost of potatoes.
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\n" ); document.write( "EQUATIONS:
\n" ); document.write( "20r + 10p = 16.20
\n" ); document.write( "30r + 12p = 23.04
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\n" ); document.write( "Multiply 1st equation by 3; Multiply 2nd equation by 2
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\n" ); document.write( "60r + 30p = 3*16.2
\n" ); document.write( "60r + 24p = 2*23.04
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\n" ); document.write( "Subtract 2nd from 1st to get:
\n" ); document.write( "6p = 3*16.2 -2*23.04
\n" ); document.write( "6p = 2.52
\n" ); document.write( "p = 0.42 (price of a pound of potatoes is 42 cents)
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\n" ); document.write( "Substitute to solve for \"r\".
\n" ); document.write( "20r + 10*0.42 = 16.2
\n" ); document.write( "20r + 4.2 = 16.2
\n" ); document.write( "20r = 12
\n" ); document.write( "r = 0.6 (price of a pound of rice is 6 cents)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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