1
1)(√5-5√2)/(√5+√2) +√10=(√5-5√2+5√2+2√5)/(√5+√2)=3√5/(√5+√2)=
=3√5(√5-√2)/(√5+√2)(√5-√2)=3√5(√5-√2)/(5-2)=√5(√5-√2)
2)√5/√2+√2/√5=(5+2)/(√10)=7/√10
3)√5(√5-√2)*7/√10=(√5-√2)*7/√2=7√2(√5-√2)/2
2
(3√3-√5)/(3√3+√5)-(3√3+√5)/(3√3-√5)=[(3√3-√5)²-(3√3+√5)²]/[(3√3)²-(√5)²]=
(3√3-√5-3√3-√5)(3√3-√5+3√3+√5)/(27-5)=-2√5*6√3/22=-6√15/11