A particular closed surface has four sides. The electric flux is \(+5.0 \mathrm{~N} \cdot \mathrm{m}^{2} / \mathrm{C}\) through side \(1,+8.0 \mathrm{~N} \cdot \mathrm{m}^{2} / \mathrm{C}\) through side 2 , and \(-9.0 \mathrm{~N} \cdot \mathrm{m}^{2} / \mathrm{C}\) through side 3.

(a) If there is no net charge enclosed by the surface, what is the flux through side 4?

(b) If the flux through side 4 is \(-8.0 \mathrm{~N} \cdot \mathrm{m}^{2} / \mathrm{C}\), how much charge is enclosed by the surface?