Answer: AC = -4(2x+1) / 2x+12.
Step-by-step explanation: To solve for AC, we can multiply both the numerator and denominator by the denominator's conjugate, which is (2x-4).
AC = -(8x + 4) / (2x+12) * (2x-4) / (2x-4)
We can simplify the denominator using the difference of squares factorization:
AC = -(8x + 4) * (2x-4) / (2x+12) * (2x-4)
AC = -(4(2x+1) * (2x-4)) / (2x+12) * (2x-4)
We can cancel the 2x-4 terms from the numerator and denominator:
AC = -(4(2x+1)) / (2x+12)
AC = -4(2x+1) / 2x+12
Therefore, AC = -4(2x+1) / 2x+12.