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

2 Answers
Jun 6, 2017

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

Jun 6, 2017

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