Question

How do you simplify `sqrt(-100) + 9sqrt(-4)`?

Answer 1

`28i`

Explanation:

`sqrt(-100)+9sqrt(-4)`
`=sqrt(-1xx10^2)+9sqrt(-1xx2^2)`
`=sqrt(-1)sqrt(10^2)+9sqrt(-1)sqrt(2^2)`

Recall that `sqrt(-1)=i` and that `sqrt(a^2)=a`.

`=10i+18i`
`=28i`