\[
f_k = f(x_k),\: x_k = x^*+kh,\: k=-\frac{N-1}{2},\dots,\frac{N-1}{2}
\]
\[
7gal(\frac{3.785l}{1gal})(\frac{1000cm^{3}}{1l})= 26495cm^{3}
\]
\begin{equation} \label{eq:poly}
P_{N-1}(x)=\sum_{j=0}^{N-1}{a_jx^j}
\end{equation}
\begin{equation} \label{eq:sys}
\left\{ P_{N-1}(x_k) = f_k\right\},\quad k=-\frac{N-1}{2},\dots,\frac{N-1}{2}
\end{equation}
\[
q2=\frac{(0.237N)x(3.5m)^{3}}{[9×10^{9}\frac{Nm^{2}}{C^{2}}]x-6×10^{-7}C}
\]
\[
q2=\frac{2.9Nm^{2}}{[9×10^{9}\frac{Nm^{2}}{C^{2}}]x-6×10^{-7}C}
\]
\[
q2=\frac{2.9Nm^{2}}{[-5400\frac{Nm^{2}}{C}]}
\]
\[
q2=-0.537×10^{-3}C}
\]
\[
F=[9×10^{9}\frac{Nm^{2}}{C^{2}}]x\frac{(-3×10^{-6}C)x(7×10^{-6}C)}{{(0.7m)^2}}=-0.3857N
\]
\[
d=\sqrt{\frac{(9×10^{9}\frac{Nm^{2}}{C^{2}})x(3.8×10^{-7}C)x(7.5×10^{-3}C)}{10N}}
\]
\[
d=\sqrt{\frac{0.256Nm^{2}}{10N}}=\sqrt{0.0256m^{2}}=0.16m
\]
\[
q2=\frac{(6×10^{-1})x(0.35m)^{2}}{[9×10^{9}\frac{Nm^{2}}{C^{2}}]x(5×10^{-6}C)}
\]
\[
q2=\frac{(6×10^{-1})x(0.35m)^{2}}{[9×10^{9}\frac{Nm^{2}}{C^{2}}]x(5×10^{-6}C)}
\]
\[
q2=1.63×10^{-6}C
\]
+
\[
F1=8.99×10^{9}*\frac{(+1.6×10^{-19})x(-1.6×10^{-19})}{(30×10^{-6})^{2}}=-2.56×10^{-19}N
\]
\[
F2=8.99×10^{9}*\frac{(+1.6×10^{-19})x(-1.6×10^{-19})}{(20×10^{-6})^{2}}=-5.75×10^{-19}N
\]