Question

How do you foil imaginary numbers?

Answer 1

Foiling imaginary numbers:

FOIL is the acronym that means, first outer, inner, last. This method is used to multiply binomials to avoid confusion and to get an accurate result. Using FOIL the imaginary numbers of complex numbers can be multiplied, as shown in the below example.

$(8+i)(2–3i)$

Using FOIL method, the imaginary numbers (here, $1$ and $3$) can be multiplied as:

$$\begin{gathered} F:8\left(2\right)=16 \\ O:8(-3i)=-24i \\ I:\left(i\right)2=2i \\ L:i(-3i)=-3i^2 \\ =-3(-1) \\ =3 \end{gathered}$$

Therefore, $(8+i)(2–3i)=16–24i+2i+3=19–22i$