Topic of Quiz : Polynomial Multiplication
Source - Apex ( Student Summer School Online Work to Pass the Class )

Use a table to compute the product below.

(x^2 + x + 8)(x-5)

A : x^3 - 4x^2 + 3x - 40
B : x^3 - 6x^2 - 3x - 40
C : x^3 - 6x^2 + 3x - 40
D : x^3 - 3x^2 + 3x - 40

(x^2 + x + 8)(x-5)

You can split it into two:

(x^2 + x + 8)(x) = x^3 + x^2 + 8x

(x^2 + x + 8)(-5) = -5x^2 - 5x - 40

x^3 + x^2 - 5x^2 + 8x - 5x - 40 =

x^3 - 4x^2 + 3x - 40.

(x^2 + x + 8)(x-5)

X(x^2 + x + 8) = x^3 + x^2 + 8x
-5(x^2 + x + 8)(x-5) = -5x^2 -5x - 40

= x^3 - 4x^2 + 3x - 40

Might be wrong haven't done these in a while

= (x2.x + x2.-5) + (x.x + x.-5) + (8.x + 8.-5)
= (x3 - 5x2) + (x2 - 5x) + (8x - 40)
= x3 - 4x2 + 3x - 40

[A]

Another way to think/do it is this:

Each "thing" has to be paired with each other "thing".

(x^2 + x + 8)(x-5)

So I have to do x^2 times x, plus x^2 times (-5), then x times x, - 5x.....

them "things" are terms

xD

GL, hated algebra