Help i dont get this

Consider symmetrically placed rectangular insulators with uniformly charged distributions of equal magnitude as shown. x y −−−−−− what is the direction of the net field at the origin?

The size of a certain cell is 2.5*10^-9m. another cell is 1.5*10^3 times larger. how large is the larger cell in scientific notation?

What is the solution set of the quadratic inequality x^2-5< or equal to 0