Hall effect with two carrier types assuming concentration n, p; relaxation times e , h

Hall effect with two carrier types assuming concentration n, p; relaxation times τ_e, τ_h; and masses me, mh, show that the Hall coefficient in the drift velocity approximations is (CGS) R_H = 1/e_C ∙ p – nb²/(p + nb)², where b = μ_c/μ_h is the mobility ratio. In the derivation neglect terms of order B² in SI we drop the c.