Answer:
[tex]9a^2-4b^2[/tex] is the correct answer.
Step-by-step explanation:
Difference of squares can be written as a^2 - b^2. This is equal to (a - b)(a + b)
In your answers, we see, 9a^2 - 4b^2. They are subtracting which is correct. 9 and 4 can also be rooted. 9 to 3 and 4 to 2 so
[tex]9a^2-4b^2[/tex] can be written as [tex](3a-2b)(3a+2b)[/tex]
