It takes 5 minutes per square foot (400/180=5) and so 5 minutes per square for 720 squares: 720x5=3,600. 3,600 minutes is equivalent to 60 hours so it takes him 60 hours.
Answer:
Step-by-step explanation:
We assume your equations are intended to be ...

Then the profit equation is ...

The partial derivatives of profit with respect to x and y are zero when profit is maximized.
∂P/∂x = 0 = -2x +2y +2
∂P/∂y = 0 = 2x -18y +94
Simplifying, these equations are ...
Substituting the first into the second gives ...
x -9(x -1) = -47
-8x = -56
x = 7
y = 7 -1 = 6
The company will maximize profit by selling 7000 panels of type A and 6000 panels of type B.
There is one<span> last step after getting </span>x<span> = </span>3<span>. You must check </span>x<span> = </span>3<span> in the original equation to be sure that </span>x<span> = </span>3<span> does not cause a zero denominator.</span>
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