Solve for x:
x^3 + 2 x^2 - 11 x - 12 = 0
Factor the left hand side.
The left hand side factors into a product with three terms:
(x - 3) (x + 1) (x + 4) = 0
Find the roots of each term in the product separately.
Split into three equations:
x - 3 = 0 or x + 1 = 0 or x + 4 = 0
Look at the first equation: Solve for x.
Add 3 to both sides:
x = 3 or x + 1 = 0 or x + 4 = 0
Look at the second equation: Solve for x.
Subtract 1 from both sides:
x = 3 or x = -1 or x + 4 = 0
Look at the third equation: Solve for x.
Subtract 4 from both sides:
x = 3 or x = -1 or x = -4