Question $4.$ A positive point charge $q=+2\mathrm{.}50nC$ is located at $x=1\mathrm{.}20m$ and a negative charge of $-2q=-5\mathrm{.}00nC$ is located at the origin, as shown in Figure $2.$

a$)$ Find the symbolic expression for the potential on the x $-$axis at an arbitrary point P between the

b$)$ Find the total electric potential at $x=0\mathrm{.}600m.$

c$)$ Find the point along the x $-$axis between the two charges where the electric potential is zero.