document.write( "Question 1027852: mixing a given quantity of 30% silver alloy with a quantity of 90% silver yields 200 units of a 54% silver alloy. How many units of each alloy were used \n" ); document.write( "
Algebra.Com's Answer #643049 by ankor@dixie-net.com(22740)\"\" \"About 
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Mixing a given quantity of 30% silver alloy with a quantity of 90% silver yields 200 units of a 54% silver alloy.
\n" ); document.write( " How many units of each alloy were used
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\n" ); document.write( "let x = amt of 30% silver alloy
\n" ); document.write( "let y = amt of 90% silver alloy
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\n" ); document.write( "Two equations
\n" ); document.write( "x + y = 200
\n" ); document.write( "x = (-y+200); we can use this form for substitution
\n" ); document.write( "and using the decimal equiv:
\n" ); document.write( ".30x + .90y = .54(200)
\n" ); document.write( "replace x with (-y+200)
\n" ); document.write( ".30(-y+200) + .90y = .54(200)
\n" ); document.write( "-.30y + 60 + .90y = 108
\n" ); document.write( "-.30y + .90y = 108 - 60
\n" ); document.write( ".60y = 48
\n" ); document.write( "y = 48/.60
\n" ); document.write( "y = 80 units of the 90% alloy
\n" ); document.write( "then
\n" ); document.write( "200 - 80 = 120 units of the 30% alloy
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\n" ); document.write( "See if that checks out in the mixture equation
\n" ); document.write( ".30(120) + .90(80) = .54(200)
\n" ); document.write( "36 + 72 = 108; confirms our solutions\r
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