If $$x^{\frac{1}{3}} + y^{\frac{1}{3}} = z^{\frac{1}{3}}$$, then $$(x + y - z)^3 + 27 xyz$$ is equal to
Given, Â Â Â $$x^{\ \frac{\ 1}{3}}+\ y^{\ \frac{\ 1}{3}} =z^{\ \frac{\ 1}{3}}$$
     $$\left(x^{\ \frac{\ 1}{3}}+\ y^{\ \frac{\ 1}{3}}\right)^3=z^{\ \frac{\ 3}{3}}$$
$$x^{\ \frac{\ 3}{3}}+y^{\ \frac{\ 3}{3}}+3.x^{\ \frac{\ 1}{3}}.y^{\ \frac{\ 1}{3}}\left(x^{\ \frac{\ 1}{3}}+y^{\ \frac{\ 1}{3}}\right)=z^{\ }$$
$$x+y+3.x^{\ \frac{\ 1}{3}}.y^{\ \frac{\ 1}{3}}\left(z^{\ \frac{\ 1}{3}}\right)=z^{\ }$$
          $$=$$>   $$x+y-z= -3.x^{\ \frac{\ 1}{3}}.y^{\ \frac{\ 1}{3}}.z^{\ \frac{\ 1}{3}}$$
Therefore   $$\left(x+y-z\right)^3+27xyz\ =\ \left(-3.x^{\ \frac{\ 1}{3}}.y^{\ \frac{\ 1}{3}}.z^{\ \frac{\ 1}{3}}\right)^3 \ +27xyz$$ = $$-27xyz+27xyz$$ = 0
       Â
Create a FREE account and get: