Factor to find the zeros of the function defined by the quadratic expression 4x2 - 24x - 108.

First, divide the expression by 4 to eliminate the numerical coefficient of the first term.

x² - 6x - 27

For quadratic expression,

a + b = - B = 6

ab = C = - 27

The values of a and b in the equations above is 9 and - 3.