Question

How do you simplify `(3 – i^7) – 2(i^6 – 5i)`?

Answer 1

You may change any `i^2=-1`

Explanation:

`=(3-i^2*i^2*i^2*i)-2(i^2*i^2*i^2-5i)`
`=[3-(-1)(-1)(-1)*i]-2[(-1)(-1)(-1)-5i]`

And if you keep good track of the `-1`'s you get:
`=(3+i)-2(-1-5i)`
`=3+i+2+10i`
`=3+2+i+10i`
`=5+11i`