SOLUTION: A certain brass alloy contains 35% zinc and 3.0% lead . Then x kg of zinc and y kg of lead are added to 240 kg of the original alloy to make a new alloy that is 40% zinc and 4.0%

Question 1069197: A certain brass alloy contains 35% zinc and 3.0% lead .
Then x kg of zinc and y kg of lead are added to 240 kg of the original alloy to make a new alloy that is 40% zinc and 4.0% lead.
(a) Show that the amount of zinc is given by
0.35(240) + x = 0.40(240 + x + y)
and that the amount of lead is given by
0.03(240) + y = 0.04(240 + x + y)
(b) Solve for x and y.
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Do not round intermediate results. Round only final answers. Round to two decimal places.
Answer by josgarithmetic(39630) (Show Source): You can put this solution on YOUR website!
This is just to get you started.
For the zinc, total new mass will become x+y+240 kg.
Amount of zinc in the new alloy is 0.35*240+x, and concentration wanted is 40%, or 0.4.

, using decimal fractions instead of percents.

Multiply left and right by :

Now just do the same thing for the lead.

Once you have the two equations, simplify them and solve the system for x and y.

Simplified system to solve can become .

RESULTS:

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