Question 1118982
{{{system(x^y=a,x^(4y)=81)}}}


{{{x^(4y)=3^4}}}
Corresponding parts suggest x=3 and y=1.


{{{a=x^y=3^1=3}}}


-


{{{x^(4y)=x^y*x^y*x^y*x^y=a^4}}}

{{{a^4=81}}}

{{{a^4=3^4}}}

Bases must be equal.

{{{a=3}}}