Simply.
`(i) (3+sqrt(3)) (2 + sqrt2)" " (ii) (6+sqrt(6))(6-sqrt(6))`
`(iii) (sqrt(3) + sqrt(2))^(2) " " (iv) (sqrt(5)-sqrt(2))(sqrt(5) + sqrt(2))`

Explanation

We have
(i) `(3+ sqrt(3)) (2+sqrt(2)) = 3xx 2 + 3 xx sqrt(2) + sqrt(3) xx 2 + sqrt(3) xx sqrt(2)`
`= 6+ 3sqrt(2) + 2sqrt(3)+sqrt(6)`
(ii) `(6+ sqrt(6))(6-sqrt(6))= (6)^(2) - (sqrt(6))^(2)" "[because (a+b)(a-b) =a^(2) -b^(2)]`
`= (36-6) = 30`
(iii) `(sqrt(3) + sqrt(2))^(2) +(sqrt(3))^(2) +(sqrt(2))^(2) + 2xx sqrt(3) xx sqrt(2)" "[because (a+b)^(2) =a^(2) + b^(2) + 2ab]`
`= 3+2+2sqrt(6) = 5 + 2 sqrt(6)`

(iv) ` (sqrt(5) - sqrt(2))(sqrt(5)+sqrt(2)) = (sqrt(5))^(2) - (sqrt(2))^(2)" "[because (a-b)(a+b) = a^(2) -b^(2)]`
`= 5-2=3`