Cho hàm số f( x ),g( x ) liên tục trên R. Các mệnh đề sau đây đúng hay sai?

A. Nếu \(\int_0^2 f (x)dx = 6\) thì  \[\int_0^2 {\left[ {2f\left( x \right) - 1} \right]} {\rm{d}}x =  - 10\]

B-Đúng 

Ta có\[\int_0^2 {\left[ {f\left( x \right) + 3g\left( x \right)} \right]} dx = \int_0^2 f \left( x \right)dx + 3\int_0^2 g \left( x \right)dx = 3 + 3.7 = 24\].

Ta có\[\int_0^2 {\left[ {f\left( x \right) + 3g\left( x \right)} \right]} dx = \int_0^2 f \left( x \right)dx + 3\int_0^2 g \left( x \right)dx = 3 + 3.7 = 24\].

Ta có \(\int\limits_0^1 {\left[ {f\left( x \right) + 2x} \right]} dx = 3 \Leftrightarrow \int\limits_0^1 {f\left( x \right)} dx + 2\int\limits_0^1 x dx = 3 \Leftrightarrow \int\limits_0^1 {f\left( x \right)} dx + 2.\frac{{{x^2}}}{2}\left| {\begin{array}{*{20}{c}}1\\0\end{array}} \right. = 3\).

Suy ra \(\int\limits_0^1 {f\left( x \right){\rm{d}}x}  = 3 - {x^2}\left| {\begin{array}{*{20}{c}}1\\0\end{array}} \right. = 3 - \left( {1 - 0} \right) = 2\).