Ada yang bisa jawab nomor 2

2a. 1/√5 . √5/√5
= (1/5)√5

2b. √(2/3) = √2/√3 . √3/√3
              = (1/3)√6

2c. 3/(2 - √3) . (2 + √3)/(2 + √3)
    = 3(2 + √3)/(4 – 3)
    = 6 + 3√3

2d. (3 - √2)/(3 + √2) . (3 - √2)/(3 - √2)
     = (9 – 6√2 + 2)/(9 – 2)
     = (11 – 6√2)/7

2e. 20(√8 - √3)/(√8 + √3)(√8 - √3)
= 20(√8 - √3)/(8 – 3)
= 4(√8 - √3)

2f. (2 – 2√5) / (4 + 2√5)
=> (2 – 2√5)(4 – 2√5) / (4 + 2√5)(4 – 2√5)
=> (8 – 4√5 – 8√5 + 20) / (16 – 20)
=> (28 – 12√5) / -4
=> -7 + 3√5

2b. √2/√3
=> √2.√3 / √3.√3
=> 1/3 √6