Question

Please help solve this complex numbers equation.
(-2-2i)(-4-3i)(7+8i)
I know what the answer is, I'm just confused on how to solve the question.

Answer 1

I don't know how to solve either. However, I think I know how to simplify. :)

Answer 2

hehe

Answer 3

Okay well help simplify I guess

Answer 4

you'd multiply all factors, expand and add

Answer 5

i*i=-1

Answer 6

What do you mean expand?

Answer 7

\(\bf {\color{brown}{ (-2-2i)(-4-3i)}}(7+8i)
\\ \quad \\
{\color{brown}{ (8+6i+8i+6i^2)}}(7+8i)
\\ \quad \\
{\color{brown}{ [8+6i+8i+6(-1)]}}(7+8i)
\\ \quad \\\
(8+6i+8i-6)(7+8i)\implies (2+14i)(7+8i)
\\ \quad \\
14+16i+98i+112i^2\implies 14+16i+98i+112(-1)
\\ \quad \\
14+16i+98i-112\implies -98+114i\)

Answer 8

you can expand (-2-2i)(-4-3i) using the FOIL rule, but using a table like this may be a better choice