हम जानते हैं कि
`x^(3)+y^(3)+z^(3)-3xyz = (x+y+z)(x^(2)+y^(2)+z^(2)-xy-yz-zx)`
`= (x + y + z)(x^(2)+y^(2)+z^(2)+2xy+2yz+2zx-3xy-3yz-3zx)" "[2xy + 2yz + 2zx]` जोड़ने व घटाने पर
`=(x+y+z)[(x^(2)+y^(2)+z^(2)+2xy+2yz+2zx - 3(xy+yz+zx)]`
`= (x+y+z)[(x+y+z)^(2)-3(xy+yz+zx)]`
`= (x+y+z)^(3)-3(xy+yz+zx)(x+y+z)=(1)^(3)-3(-1)xx 1`
`x^(3) + y^(3) + z^(3)-3(-1)=1-3(-1)=1+3=4`
`x^(3)+y^(3)+z^(3)+3=4" "rArr" "x^(3)+y^(3)+z^(3)=1`
