(3х-2)(3х+2)(9х²+4)

To expand the given expression \( (3x-2)(3x+2)(9x^2+4) \), we will use the distributive property of multiplication.

First, we will multiply the first two terms: \( (3x-2)(3x+2) = 9x^2 + 6x - 6x - 4 = 9x^2 - 4 \)

Next, we will multiply this result by the third term: \( (9x^2 - 4)(9x^2+4) = 81x^4 + 36x^2 - 36x^2 - 16 = 81x^4 - 16 \)

Therefore, the expanded expression is \( 81x^4 - 16 \).