C-9 2(a) 3(a) Помогите пж.

Question

C-9
2(a)
3(a)
Помогите пж.

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Answer 1

2)x^3+18=0
  x^3=-18; x=∛(-18)=-∛18;
3)√(4-√7)(√(4+√7)=√(4^2-(√7)^2)=√(16-7)=√9=3