Can someone answer this: (1-3*x*)*(2+*i*), and also explain the FOIL system?

JoshSulentic
Sep 20, 2017

#1**+2 **

Can someone answer this: (1-3x)*(2+i), and also explain the FOIL system?

I do not usually teach this method but I shall explain it since you ask.

(1-3x)*(2+i)

The first bracket has 2 terms, they are 1 and -3x

The second bracket also has 2 terms, they are 2 and i

F stands for first that is 1*2 = 2

O stands for outside so that is 1*+i = i

I stands for inner -3x*2 = -6x

L stands for last -3x*i = -3xi

Add them all together and you have

\((1-3x)(2+i)\\=2+i+-6x+-3xi\\ =2+i-6x-3xi\)

i is often used to denote an imaginary number but since this is a low level question I assume that i is a pronumeral the same as x is. :)

Melody
Sep 20, 2017