If x+y = 7 find ( frac1x^3 + frac1y^3 )

Put x = 5, y = 2 [Because these value are satisfying the equations]

⇒ \(\frac{1}{({5}^{3})}\) + \(\frac{1}{({2}^{3})}\) = \(\frac{125+8}{1000}\) = 0.133