On b-generalized derivations in prime rings

Let R be a prime ring of characteristic different from 2 with Utumi quotient ring U and extended centroid C, f (x(1), ..., x(n)) be a multilinear polynomial over C, which is not central valued on R. Suppose F, G are non zero b-generalized derivations of R such that puF(u) + F(u)uq = G(u(2)), p + q is not an element of C for all u is an element of f(R). Then we describe all the possible representations of F, G.