We know that,
#(1)log_zA=P<=>A=z^P#
We take ,the base of log as #10#
Let ,
#logx/(a^2+ab+b^2)=logy/(b^2+bc+c^2)=logz/(c^2+ca+a^2)=k#
So ,
#logx=k(a^2+ab+b^2)=>x=10^(k(a^2+ab+b^2))#
#logy=k(b^2+bc+c^2)=>y=10^(k(b^2+bc+c^2)#
#logz=k(c^2+ca+a^2)=>z=10^(k(c^2+ca+a^2)#
Now ,
#x^(a-b)=10^(k(a-b)(a^2+ab+b^2))=10^(k(a^3-b^3)#
#y^(b-c)=10^(k(b-c)(b^2+bc+c^2))=10^(k(b^3-c^3)#
#z^(c-a)=10^(k(c-a)(c^2+ca+a^2))=10^(k(c^3-a^3)#
Hence ,
#x^(a-b)*y^(b-c)*z^(c-a) =10^(k(a^3-b^3) )*10^(k(b^3-c^3))*10^(k(c^3-a^3)#
#x^(a-b)*y^(b-c)*z^(c-a) =10^((k(a^3-b^3) )+(k(b^3-c^3))+(k(c^3-a^3)#
#x^(a-b)*y^(b-c)*z^(c-a) =10^(k(a^3-b^3+b^3-c^3+c^3-a^3)#
#x^(a-b)*y^(b-c)*z^(c-a) =10^(k(0)) =10^0=1#
#x^(a-b)*y^(b-c)*z^(c-a) =1#