Nếu \(\int\limits_{0}^{7}{f\left( x \right)\text{d}x}=18\) và \(\int\limits_{1}^{7}{f\left( x \right)\text{d}x}=9\) thì \(\int\limits_{0}^{1}{f\left( x \right)\text{d}x}\) bằng

* Hướng dẫn giải

\(\int\limits_0^1 {f\left( x \right){\rm{d}}x}  + \int\limits_1^7 {f\left( x \right){\rm{d}}x}  = \int\limits_0^7 {f\left( x \right){\rm{d}}x}  \Leftrightarrow \int\limits_0^1 {f\left( x \right){\rm{d}}x}  = \int\limits_0^7 {f\left( x \right){\rm{d}}x}  - \int\limits_1^7 {f\left( x \right){\rm{d}}x}  = 18 - 9 = 9\)