Factor completely...................

Answer:
Final answer is A. [tex]9(3x+1)(3x-2)[/tex].
Step-by-step explanation:
Given expression is [tex]81x^2-27x-18[/tex].
[tex]81x^2-27x-18[/tex]
[tex]=9(9x^2-3x-2)[/tex]
We can factor that by splitting middle term into two parts then do grouping as shown below:
[tex]=9(9x^2-6x+3x-2)[/tex]
[tex]=9(3x(3x-2)+1(3x-2))[/tex]
[tex]=9(3x+1)(3x-2)[/tex]
Which correctly matches with choice A. [tex]9(3x+1)(3x-2)[/tex].
Hence final answer is A. [tex]9(3x+1)(3x-2)[/tex].