document.write( "Question 1188336: A certain alloy is 30% copper, 45% zinc and 25% iron. By adding 25 grams of zinc to it, the
\n" ); document.write( "new alloy now has 56% zinc. How much copper is in the alloy? \n" ); document.write( "
Algebra.Com's Answer #819409 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Instead of doing your homework for you, I'll do a different problem exactly like\r\n" );
document.write( "yours step-by-step which you can use as a model to do yours by.

\n" ); document.write( "A certain alloy is 26% copper, 46% zinc and 28% iron. By adding 40 grams of zinc
\n" ); document.write( "to it, the new alloy now is 55% zinc. How many grams of each metal is in the
\n" ); document.write( "(ORIGINAL) alloy?
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document.write( "Let x = the total number of grams of ORIGINAL alloy.\r\n" );
document.write( "Then \r\n" );
document.write( "0.26x = the number of grams of copper.\r\n" );
document.write( "0.46x = the number of grams of zinc.\r\n" );
document.write( "0.28x = the number of grams of iron.\r\n" );
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document.write( "We start with 0.46x grams of zinc and add 40 grams of zinc to that. That gives\r\n" );
document.write( "us 0.46x + 40.  That increases the amount from x grams to x+40 grams. So adding\r\n" );
document.write( "that zinc caused there to now be 55% of that increased amount of x+40.\r\n" );
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document.write( "0.46x + 40 = 0.55(x+40)\r\n" );
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document.write( "We can remove the decimals by multiplying through by 100.\r\n" );
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document.write( "46x + 4000 = 55(x+40)\r\n" );
document.write( "46x + 4000 = 55x + 2200\r\n" );
document.write( "     -9x = -1800\r\n" );
document.write( "       x = -1800/(-9)\r\n" );
document.write( "       x = 200\r\n" );
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document.write( "So the amount of original alloy was 200 grams.  So\r\n" );
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document.write( "0.26x = the number of grams of copper = 0.26(200) = 52 grams\r\n" );
document.write( "0.46x = the number of grams of zinc = 0.46(200) = 92 grams\r\n" );
document.write( "0.28x = the number of grams of iron = 0.28(200) = 56 grams\r\n" );
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document.write( "Now do yours exactly the same way, step-by-step.\r\n" );
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document.write( "Edwin
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