1.Transform the expression disappearing the root from the consequent.

1/(5)1/3-(2)1/3 (1/3 is the exponent)

2.Prove that for evry real x, y and z it's true:

(x-y)3+(y-z)3+(z-x)3=3*(x-y)*(y-z)*(z-x)

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- Sep 18th 2008, 12:16 PMblerttaequality
1.Transform the expression disappearing the root from the consequent.

1/(5)1/3-(2)1/3 (1/3 is the exponent)

2.Prove that for evry real x, y and z it's true:

(x-y)3+(y-z)3+(z-x)3=3*(x-y)*(y-z)*(z-x) - Sep 18th 2008, 12:38 PMhwhelper
- Sep 18th 2008, 12:43 PMicemanfan
For the first problem, multiply top and bottom by $\displaystyle 5^{2/3} + 5^{1/3}2^{1/3} + 2^{2/3}$.

For the second problem, it's just a matter of multiplying out both sides of the expression. Use binomial expansion on the left side.