Respuesta :

Answer:

x = -1, 0, and 4

Step-by-step explanation:

Step 1:  Set the expression equal to zero.  Solving means to find out what values of x make the equation equal zero.

  3x³ - 9x² - 12x = 0

Step 2:  Factor out the largest common factor is there is one.  

Here the largest common factor is 3x.  Now we have

3x(x² - 3x - 4) = 0

Step 3:  Factor the quadratic expression x² - 3x - 4

3x(x - 4)(x + 1) = 0                  (two numbers that add up to -3 and multiply to -4)

Step 4:  Set each term equal to zero and solve..

3x = 0,    so x = 0     (divide both sides by 3 to isolate x)

x - 4 = 0,  so x = 4    (add 4 to both sides to isolate x)

x + 1 = 0, so x = -1    (subtract 1 from both sides to isolate x)

So our solutions are

x = -1, 0, and 4