81^(0,25)-(1/9)^(1/2)+(0,5)^(-2)=4
81^(0,25)=81^(1/4)=3
(1/9)^(-1/2)=1/(1/9)^(1/2)=3
(0,5)^(-2)=(1/2)^(-2)=1/(1/2)^2=4
3-3+4=4
