Dear sir please.solve question 3b

a^x / a^y = ax-y
Then, the first term becomes:
a^{(x-y)( x2 +xy + y2)}  = a^{(x3 - y3)}
Proceeding like this:
The given expression reduces to,
a^{(x3 - y3)} . a^{( y3 - z3)} . a^{(z3 - x3) =} a^{( x3-y3+y3-z3+z3-x3)} = a⁰ = 1