If x=Σ_n=0^∞ a^n, y=Σ_n=0^∞ b^n, z=Σ_n=0^∞ c^n, where a, b, c are in A.P. and | a |<1,| b |<1,| c |<1, abc ≠ 0, then:

If $\displaystyle x=\sum_{n=0}^{\infty} \mathrm{a}^{\mathrm{n}}, y=\sum_{n=0}^{\infty} \mathrm{b}^{\mathrm{n}}, z=\sum_{n=0}^{\infty} \mathrm{c}^{\mathrm{n}}$, where a, b, c are in A.P. and $\displaystyle |\mathrm{a}|<1,|\mathrm{~b}|<1,|\mathrm{c}|<1$, $\displaystyle \mathrm{abc} \neq 0$, then :