Question

How do you factor `3x^2 - 12`?

Answer 1

3(x-2)(x+2)

Explanation:

when factorising follow these steps
(1) is there a common factor?
(2) is it a trinomial ?
(3) is it a difference of 2 squares ?

in this case there is a common factor of 3 (1)

`3x^2 - 12 = 3(x^2 -4)`
inside the bracket is a difference of 2 squares (3)
`x^2 -4 = (x-2)(x+2)`
so `3x^2 - 12 = 3(x-2)(x+2)`