Question

How to solve the 3x cube - 12x

Answer 1

Answer:

3 x ( x 2 − 4 )

Rewrite  

4  as  2 ^2x3 x ( x 2 − 2 ^2 )

Answer 2

Answer:

$3 {x}^{3} - 12x = 0 \\ x(3 {x}^{2} - 12) = 0$

Now we get,

$x = 0$

and

$3 {x}^{2} - 12 = 0 \\ 3 {x}^{2} = 12 \\ {x}^{2} = 4$

x = +2, -2.

So we will have X = 0, -2, +2.