Nếu , thì bằng

Câu hỏi :

Nếu \(\int\limits_1^2 {f\left( x \right){\rm{d}}x = 3} \), \(\int\limits_2^5 {f\left( x \right){\rm{d}}x = - 1} \) thì \(\int\limits_1^5 {f\left( x \right){\rm{d}}x\,} \) bằng