有理數及無理數!plz come!10 marks!

1.
(a). √338 = √169 x 2 = 13 √2
(b). √169 / 16 = 13 / 16
(c). - √0.81 = - 0.9
(d). - √(4 + 29 / 49) = - √225 / 49 = - 15 / 7

2.
(a). 6 √3 + 5 √3 - 3 √3 = 8 √3
(b). √125 - √5
= √25 x 5 - √5
= 5 √5 - √5
= 4 √5
(c). 5 √2 - √8 + 3 √2
= 5 √2 - √4 x 2 + 3 √2
= 5 √2 - 2 √2 + 3 √2
= 6 √2
(d). √8 x √18
= √144
= 12

1a) 13√2

b) √13/4

c) -0.9

d)15/7


2a) 8√3


b) 4√5

c) 6√2

d) 12