On two infinite parallel planes are evenly distributed charges to the surface density σ 1 = σ, σ 2 = -2σ, where σ = 20 nC / m ^ 2. Requires: 1) find the intensity E of the electric field in three areas: the left and right between the planes, 2) in the figure indicate the direction of the vector E for each field.

Detailed solution shorthand terms, formulas and laws used in the decision, the withdrawal of the calculation formula and the response.
If you have any questions to address, please. I try to help.