Let and a = 4, b = –2.

Show that:


A + (B + C) = (A + B) + C


Given A = B = and C =


LHS = A + (B + C) =


LHS =


LHS =


RHS = (A + B) + C =


RHS =


RHS =


Clearly LHS = RHS =


Hence,


A + (B + C) = (A + B) + C …proved


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