求由方程$xy = e^{x + y}$所确定的隐函数$x = x(y)$的导数$\dfrac{dx}{dy}$.

设连续函数$f(x)$满足$f(x) = x^2 - \int_{0}^{2}f(x)dx$，则$\int_{0}^{2}f(x)dx =$（　　）.

不定积分$\int \dfrac{x^3}{x}dx =$（　　）.