sqrt(25)-sqrt(45)=sqrt(5*5)-sqrt(9*5)=sqrt(5)*sqrt(5)-sqrt(9)*sqrt(5)=
=sqrt(5)*sqrt(5)-3*sqrt(5)=sqrt(5)*(sqrt(5)-3)
(sqrt(25)-sqrt(45)):sqrt(5)=[b]sqrt(5)-3[/b]
б)
∛(625)-∛5=∛(5*5*5*5)-∛5= ∛(5^3*5)-∛5=∛(5^3)*∛5-∛5=5*∛5-∛5=
=∛5*(5-1)=[b]4∛5[/b]