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

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