9.4.7 Curvilinear integrals

3) Problem: Calculate the line integral using the polygonal \( L \) : \[ \int_{L}\left(x^{3}+y\right) d x+\left(x+y^{2}\right) d y \] where 1) \( L: A B C, 2) L: A B C A, A(7 ; 7), B(3 ; 7), C(3 ; 5) \).