Question

How do you simplify `(-6-8i)(-3+8i)`?

Answer 1

`82-24i`

Explanation:

You can just multiply everything out as in regular brackets, remembering that `i^2 = -1`.
So the expansion of `(-6-8i)(-3+8i)` is:
`(-6)(-3) + (-6)(8i) + (-8i)(-3) + (-8i)(8i)`
`= 18 - 48i + 24i -64i^2`
`= 18 - 64i^2 + (-48+24)i`
`= 18 + (-64)*(-1) -24i`
`= 18 + 64 -24i`
`= 82 - 24i`

Answer 2

`82-24i`

Explanation:

`"expand the brackets using FOIL"`

`rArr(-6-8i)(-3+8i)`

`=18-48i+24i-64i^2larr i^2=-1`

`=18-24i+64`

`=82-24i`