For the redox reaction,xFe2+ + yCr2O72- + zH+ →  Fe3+ + Cr3+ + H2Ox, y and z are

To balance a redox reaction, balance effected atoms(I) Fe2+ →  Fe3+       (Fe-balanced)(II) Take oxidation number of two Cr-atomCr+62O72- →  2Cr+3               (Cr-balanced)Take total (oxidation number) of each atom (oxidized, reduced) cross-multiplied by change in oxidation number and addI×6+II×1 6Fe2++Cr2O72- →  6Fe+3+2Cr+3Balance O, by H2O .... + 7H2OBalance H, by H+..... + 14H+The balanced equation is 6Fe+2+Cr2O7-2+14H+→6Fe+3+2Cr+3+7H2OThus, x = 6          y = 1          z = 14