64x² - 36 factors to be (8x + 6)(8x - 6)
Option C is your answer.
HOWEVER, I cannot tell what the operation is supposed to be performed because of the way it is showing up above (see attached pic). So I can also just simplify it.
64x² - 36 becomes 4(16x² - 9) or 4(4x - 3)(4x + 3)
64x² + 36 becomes 4(16x² + 9)
Option C is your answer.
HOWEVER, I cannot tell what the operation is supposed to be performed because of the way it is showing up above (see attached pic). So I can also just simplify it.
64x² - 36 becomes 4(16x² - 9) or 4(4x - 3)(4x + 3)
64x² + 36 becomes 4(16x² + 9)