Let a - 4 = x b - 3 = y c - 1 = z Adding these equations we get: x + y + z = a - 4 + b - 3 + c - 1 = a + b + c - 8 = 8 - 8 = 0 = x + y + z = 0 We have an identity if x + y + z = 0 then x3+y3+z3−3xyz=0 (a−4)3+(b−3)3+(c−1)3−3(a−4)(b−3)(c−1)=0