Giả sử \(\int\limits_{0}^{9}{f\left( x \right)\text{d}x}=37\) & \(\int\limits_{9}^{0}{g\left( x \right)\text{d}x}=16\).

* Hướng dẫn giải

\(I = \int\limits_0^9 {\left[ {2f\left( x \right) + 3g(x)} \right]{\rm{d}}x}  = \int\limits_0^9 {2f\left( x \right){\rm{d}}x}  + \int\limits_0^9 {3g\left( x \right){\rm{d}}x}  = 2\int\limits_0^9 {f\left( x \right){\rm{d}}x}  - 3\int\limits_9^0 {g\left( x \right){\rm{d}}x}  = 26\)