Question 1171170
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            Your approach is TOTALLY WRONG.

            See my solution below and  WATCH  attentively  EVERY  MY  STEP.



<pre>
Let x be the total weight, in pounds.  THEN


    copper = {{{x/2-16}}};  tin = {{{x/3-12}}};  lead = {{{x/4-4}}}.


Your equation is the equation for the total


    copper  + tin    + lead = x,   or


    {{{x/2-16}}}  + {{{x/3-12}}} + {{{x/4-4}}} = x.


To solve it, multiply all the terms by 12. You will get


    6x - 192 + 4x - 144 + 3x - 48 = 12x

    13x = 12x + 192 + 144 + 48

    13x - 12x = 384.

        x     = 384  pounds.


<U>ANSWER</U>.  the total weight of the alloy is 384 pounds.
</pre>

Solved.



It is really good problem (!)



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<U>comment from student</U> : I made an error in posting problem: Should be; 4 lbs. more than 1/4 is lead. 
Sorry for error. Would that make a difference in answer?




<U>My responce</U> :  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ARE &nbsp;YOU &nbsp;SCOFFING &nbsp;ME &nbsp;&nbsp;? ? ?