SOLUTION
(a) To break even, total revenue must be equal to total cost.
So we equate the revenue function to the cost function and find x which is the number of units, we have
[tex]\begin{gathered} C(x)=145x+70,560 \\ R(x)=285x \\ 145x+70,560=285x \\ 70,560=285x-145x \\ 140x=70,560 \\ x=\frac{70,560}{140} \\ x=504\text{ units} \end{gathered}[/tex]Hence number of units sold to break even is 504 units
Amount coming and going out, we put x for 504 into any of the equation, we have
[tex]\begin{gathered} R=285\times504 \\ R=143,640 \end{gathered}[/tex]Hence the answer is 143,640
The profit function, we subtract cost function from revenue, we have
[tex]\begin{gathered} P(x)=285x-(145x+70,560) \\ P(x)=285x-145x-70,560 \\ P(x)=140x-70,560 \end{gathered}[/tex]Hence the answer is
P(x) = 140x - 70,560