Chọn A
Ta có: \(\int _{-1}^{4}\left[5f\left(x\right)-3\right]dx =5\int _{-1}^{4}f\left(x\right)dx -\left. 3x\right|_{-1}^{4} =5\int _{-1}^{4}f\left(x\right)dx -15\)
\(\Rightarrow \int _{-1}^{4}\left[5f\left(x\right)-3\right]dx =5\Leftrightarrow 5\int _{-1}^{4}f\left(x\right)dx -15=5\Leftrightarrow \int _{-1}^{4}f\left(x\right)dx =4\)