<PRE><B>Question 1026587</B>
A metal worker has a metal alloy that 30% copper and another one is 55% copper. how many kilograms of each alloy should the metalworker combine to make 50kg of a 50% copper alloy? 
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Equation:
copper + copper = copper
0.30x + 0.55(50-x) = 0.50*50 kg
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30x + 55*50 - 55x = 50*50
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-25x = -5*50
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x = 10 kg (amt. of 30% needed)
50-x = 40 kg (amt. of 55% needed)
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Cheers,
Stan H.
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