Ответ:

1) (33 / √17 - √6) * (√17 + √6) =

= 33(√17 + √6) / (√17 + √6)(√17 - √6) =

= 33(√17 + √6) / 17 - 6 =

= 33(√17 + √6) / 11 =

= 3(√17 + √6)

2) 18 / (3+√3) =

= 18(3-√3) / (3+√3)(3-√3) =

= 18(3-√3) / (9 - 3) =

= 18(3-√3) / 6 =

= 3(3-√3) = 9 - 3√3

3) 1 / ³√2-1 =

= ((³√2)^2 + ³√2 + 1) / (2 - 1) =

= (³√2)^2 + ³√2 + 1

^2 это квадрат