根号5分之根号20+根号5-2
=根号4+根号5-2
=2-2+根号5
=根号5
根号3分之根号12+根号27
=根号4+根号(9*3)
=2+3根号3
根号20=2*根号5
根号12=2*根号3
根号27=3*根号3
供参考,简化后自己算应该没问题了
(√20+√5)/√5 - 2
=√20/√5 +√5/√5 - 2
=√(20/√5) + 1 - 2
= √4 -1
= 2 - 1
= 1
√12/√3 + √27
= √(12/3) + √(9*3)
= √4 + 3√3
= 2+3√3
(√20+√5)/√5 - 2
=√5(√4 +1)/√5 - 2
= √4 +1-2
= 3 - 2
= 1
(√12 + √27)/√3
= √3(√4+ √9)/√3
= √4 + √9
= 2+3
= 5