Question 1167449
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Let D be the amount invested in desktop computers.

Then the amount invested in the notebook computers is (50000-D).


The total profit equation is

    0.2*D + 0.25*(50000-D) = 0.23*50000.


From the equation

    D = {{{(0.23*50000 - 0.25*50000)/(0.2 - 0.25)}}} = 20000.


<U>ANSWER</U>.  The amount invested at desktop computers is 20000 dollars.


<U>CHECK</U>.  0.2*20000 + 0.25*(50000 - 20000) = 11500 = 0.23*50000.   ! Correct !
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Solved.