Tolong dibantu y guys+ Caranya

no1
1 / (√5 +1)
= (1 x (√5 -1)) / ((√5 +1) x (√5 -1))
= (√5 -1) / (5 - 1)
= (√5 -1) / 4

no2
3 / (4+√2)
= (3 x (4-√2)) / ((4+√2) x (4-√2))
= (12-3√2) / (16 - 2)
= (12-3√2) / 14

no3
2√5 / (2+√5)
= (2√5 x (2-√5)) / ((2+√5) x (2-√5))
= (4√5 - 10) / (4-5)
= (4√5 - 10) / -1
= -(4√5 - 10)

no4
(√3 + 2) / (√5 - 1)
= ((√3 + 2) x (√5 + 1)) / ((√5 -1) x (√5 +1))
= (√15 + √3 + 2√5 + 2) / (5 - 1)
= (√15 + √3 + 2√5 + 2) / 4