I need help with Complex Numbers? Thanks!?

Question

Help is greatly appreciated. I'm not sure how to do these problems. Help in steps please. The (i) is not under the radical.

1.) (1 + √7i)(-2 - √5i)

2.) (2 + √-3)(-1 + √-12)

3.) Write an equation with solutions i and -i

Thanks everyone!

Answer 1

Question 1
- 2 - √5 i - 2√7i + √35
(√35 - 2) - (√5 + 2√7) i

Question 2
(2 + √3 i)(- 1 + √12 i)
- 2 + (2√12 - √3)i + √36 i²
- 8 + (2√12 - √3) i
- 8 + (√3) i

Question 3
Z² + 1 = 0