(3х-2)(3х+2)(9х²+4)

To expand the expression \((3x-2)(3x+2)(9x^2+4)\), we can first multiply the first two binomials using the distributive property:

\((3x-2)(3x+2) = 3x * 3x + 3x * 2 - 2 * 3x - 2 * 2 = 9x^2 + 6x - 6x - 4 = 9x^2 - 4\)

Now, we multiply this result by the third binomial:

\((9x^2 - 4)(9x^2 + 4) = 9x^2 * 9x^2 + 9x^2 * 4 - 4 * 9x^2 - 4 * 4 = 81x^4 + 36x^2 - 36x^2 - 16 = 81x^4 - 16\)

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