Area Between Curves Calculation Steps

I.

The area between the curves can be expressed as $A = \int_{0}^{4} [(5 * x - x^2) - x] \;dx$.

II.

Simplifying the integrand gives $\int_{0}^{4} (4 * x - x^2) \;dx$.

III.

Evaluating the integral yields an area of $\frac{32}{3}$.

Which of the above statements are correct for finding the area between the curves $f(x) = 5 * x - x^2$ and $g(x) = x$ on the interval [0, 4]?