Question

What is the standard form of `y= (x – 1) (x + 2) (x + 3)`?

Answer 1

`y=x^3+4x^2-9`

Explanation:

Expand the formula and ensure the power and coefficient go first.

`y=(x-1)(x+2)(x+3)`
`=(x^2+2x-x-3)(x+3)` (Use FOIL on the first two terms)
`=(x^2+x-3)(x+3)` (Simplify)
`=x^2(x+3)+x(x+3)-3(x+3)` (Distribute the `(x+3)`)
`=x^3+3x^2+x^2+3x-3x-9`
`=x^3+4x^2-9` (Simplify)