$\begin{aligned} & \overrightarrow{\mathrm{E}}=2 x \hat{\mathrm{i}} \\ & \phi=\overrightarrow{\mathrm{E}} \cdot \overrightarrow{\mathrm{A}}\end{aligned}$
$\begin{aligned} & \phi_{\text {in }}=-4 \times 4=-16 \mathrm{Nm}^2 / \mathrm{c} \\ & \phi_{\text {out }}=8 \times 4=32 \mathrm{Nm}^2 / \mathrm{c} \\ & d_{\text {net }}=\phi_{\text {in }+} \phi_{\text {out }}=-16+32=16 \mathrm{Nm}^2 / \mathrm{c}\end{aligned}$