Question

Question #d629b

Answer 1

I tried this:

Explanation:

a) `(-i*-i*-i*-i)×3(i*i*i)=(i^2*i^2)×3(-1*i)=(-1*-1)×3(-i)=-3i`
Where I used the fact that `i^2=-1`.

b) I multiply the 2 brackets:
`4*7-4*3i+7*3i-3*3i^2=28-12i+21i+9=37+9i`