How do you simplify (-3 + i)(2 + 7i) ?

1 Answer
Jan 22, 2016

(-3+i)(2+7i)=-13-19i=-(13+19i)

Explanation:

Remembering that i^2=-1

You can think that (a+ib) is like a binomial, thus:

(-3+i)(2+7i)=(-3times2-3times7i+2timesi+7i^2)=

=-6-21i+2i+7times(-1)=(-6-7)+(-21+2)i=-13-19i=-(13+19i)