Cho intlimits01 fleft( x right)rmdx = 3, intlimits13 fleft( x right)rmdx = -

Cho $\int\limits_0^1 {f\left( x \right){\rm{d}}x} = 3$, $\int\limits_1^3 {f\left( x \right){\rm{d}}x} = - 1$. Tính tích phân $\int\limits_3^0 {f\left( x \right){\rm{d}}x} $.