Nếu \(\int\limits_{1}^{2}{f\left( x \right)\,\text...

Câu hỏi: Nếu \(\int\limits_{1}^{2}{f\left( x \right)\,\text{d}x}=3,\,\,\int\limits_{2}^{5}{f\left( x \right)\,\text{d}x}=-\,1\) thì \(\int\limits_{1}^{5}{f\left( x \right)\,\text{d}x}\) bằng      

A -2

B 2

C 3

D 4