In this paper, results of the broadband dielectric spectroscopy of 0.4PbMg(1/3)Nb(2/3)O(3)-0.3PbZn(1/3)Nb(2/3)O(3)-0.3PbSc(1/2)Nb(1/2)O(3) (0.4PMN-0.3PZN-0.3PSN) are presented. Dielectric spectra of these solutions were investigated in a broad frequency range from 20 Hz to 100 GHz. Very strong and broad dielectric relaxation was analyzed in terms of distribution of relaxations times, using Tichonov regularization method. It revealed slowing down of the longest relaxation and the mean relaxation times in the agreement with the Vogel-Fulcher law and the Arrhenius law, respectively..