\(\phi=\overrightarrow{\mathrm{E}} \cdot \overrightarrow{\mathrm{A}}\)
\(\phi_{\text {in }}=-4 \times 4=-16 \mathrm{Nm}^2 / \mathrm{c}\)
\(\phi_{\text {out }}=8 \times 4=32 \mathrm{Nm}^2 / \mathrm{c}\)
\(d_{\text {net }}=\phi_{\text {in }} \phi_{\text {out }}=-16+32=16 \mathrm{Nm}^2\)