What is the measure of rcd in the figure below

Which shows one way to determine the factors of  x3  +  5x2  –  6x  –  30 by grouping? x(x2  –  5)  +  6(x2  –  5)x(x2  +  5)  –  6(x2  +  5)x2(x  –  5)  +  6(x  –  5)x2(x  +  5)  –  6(x  +  5)

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?

(-y to the power of 2 - 4y- to the power of 2 -6 y +3)