A.\(\int {\left[ {f\left( x \right) - g\left( x \right)} \right]} dx = \int {f\left( x \right)dx - \int {g\left( x \right)dx} } \)
B.\(\int {2f\left( x \right)dx}  = 2\int {f\left( x \right)dx} \)
C.\(\int {\left[ {f\left( x \right) + g\left( x \right)} \right]dx}  = \int {f\left( x \right)dx}  + \int {g\left( x \right)dx} \)
D.\(\int {\left[ {f\left( x \right)g\left( x \right)} \right]dx}  = \int {f\left( x \right)dx} .\int {g\left( x \right)dx} \)