Question

How to solve (-2-2i)(-4-3i)(7+8i)

Answer 1

Step 1-F.O.I.L.: (-2-2i)(-4-3i)
8+6i+8i+3i^2
We know i^2=-1, so...
8+14i-3
5+14i

Step 2-F.O.I.L. again: (5+14i)(7+8i)
35+40i+98i+112i^2
35+138i-112
-77+138i

Note: "F.O.I.L." stands for "First, Outer, Inner, Last". In other words, distribute the terms of the first binomial to the other, in that order. So, (5+14i)(7+8i) should be done as follows:

5*7=56
5*8i=40i
14i*7=98i
14i*8i=112i^2