Final answer:
The two binomials that are factors of 81x² – 36 are (9x + 6) and (9x - 6), because the expression is a difference of squares.
Step-by-step explanation:
To find the two binomials that are factors of 81x² – 36, we can look for binomials that when multiplied give us this expression. The given expression is a difference of squares and can be factored as follows:
(9x)^2 - (6)^2 = (9x + 6)(9x - 6)
So the correct factors are (9x + 6) and (9x - 6).