Question 765069
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Use the identity: {{{(x - y)^3 = x^3 - y^3 - 3*x*y*(x - y)}}}

Since we know x - y = 6 and xy = 1, substitute in the equation.

{{{6^3 = x^3 - y^3 - 3*1*6}}}

{{{216 = x^3 - y^3 - 18}}}

{{{x^3 - y^3 = 234}}}

:)

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