I.10.22 Flux of the vector field

condition: Calculate the flow of the vector field \( \vec{a} \) through a closed surface bounding the body \( V \) a) using the Gauss-Ostrogradsky formula, b) directly: \[ \vec{a}=2 y^{2} \vec{\imath}+x^{2} \vec{\jmath}+4 x z \vec{k}, \quad V:\left\{\begin{array}{c} x=0, y=0, z=0 \\ z=2, x+y=3 \end{array} .\right. \]