sqrt(9-4sqrt(5))=sqrt(2-sqrt(5))^2)=|2-sqrt(5)|=sqrt(5)-2,
так как 2 < sqrt(5) и 2-sqrt(5) < 0
|2-sqrt(5)|=-(2-sqrt(5))=sqrt(5)-2
sqrt(9-4sqrt(5))-sqrt(5)=sqrt(5)-2-sqrt(5)=-2
Ответ: -2
sgrt(9-4sgrt(5)-sgrt(5)=
= (sgrt(2-sgrt(5))^2-sgrt((5)=
= sgrt(4)-sgrt(5)|=sgrt(5)-sgrt(4)-sgrt(5)=-2
Ответ:-2.