Using Coulomb's law:
[tex]\begin{gathered} F_{12}=K\cdot\frac{q1\cdot q2}{r^2} \\ F_{12}=(8.988\times10^9)\cdot(\frac{(2.6\times10^{-6})(3.75\times10^{-6})}{0.25^2}) \\ F_{12}=1.402N \end{gathered}[/tex][tex]\begin{gathered} F_{32}=K\cdot\frac{q3\cdot q2}{r^2} \\ F_{32}=(8.988\times10^9)\cdot(\frac{(2.6\times10^{-6})(3.75\times10^{-6})}{0.25^2}) \\ F_{32}=1.402N \end{gathered}[/tex]Now, we can calculate the net force:
[tex]\begin{gathered} F_x=F_{12}cos(60)+F_{32} \\ F_x=2.103N \end{gathered}[/tex]Answer:
+ 2.103 N