7x10^-9 point charge is on the x-axis at x=-3.0m, and a -2.0x10^-9 point charge is on the x-axis at x=0.

A +5.7x10^-9 point charge is on the x-axis at x=-3.0m, and a -2.0x10^-9 point charge is on the x-axis at x=0.00m.

a. Determine the net electric field (magnitude and direction) on the x-axis at x= +1 m.

b. Determine the net electric force (magnitude and direction) exerted on a -3.0x10^-9 when it is located at x = +1 m.

answer to a is -14,777 N/C left

answer to b is 0.0442 N right

How do I get to these answers?

thanks