12. x2 - 4x - 6 = x2 + 4x - 2

The required value of x is - 1/2.

Step-by-step explanation:

We have to find the value of x from the given equation.

x² - 4x - 6 = x² + 4x - 2

Step: Add the like terms.

x² - 6 + 2 = x² + 4x + 4x

Step: Add the unlike terms.

x² - 6 + 2 = x² + 4x + 4x x² - 4 = x² + 8x

Step: Arrange in simplest form.

x² - 4 = x² + 8x x² - x² = 8x + 4 0 = 8x + 4 - 4 = 8x 8x = - 4 x = - 4/8 x = - ½

Therefore, the required value of x is - 1/2.