The following three point charges are on the $?-$axis:

${?}_1=3\mathrm{.}0?$ is at $=-3\mathrm{.}0?.$

${?}_2=-2\mathrm{.}0?$ is at the origin.

${?}_3=3\mathrm{.}0?$ is at $=3\mathrm{.}0?.$

Find the total electric force on ${?}_1.$

these are the answers my prof provided us with:

= 0.00375 N