2.They will fix the computer soon, won't they?
Yes , they will
3. People speak English in Australia, don't they?
Yes, they do
4.Mother has already cooked dinner, hasn't she? ( не уверена)
Yes, she has
5. Your brother hid this book, didn't he?
Yes, he did.
6. They will build a swiming pool on Rose street , won't they?
Yes, they will.
Удачи!