Let's first expand the left side of the equation:

(3x+4)·(3x -4)
= 3x(3x) + 3x(-4) + 4(3x) + 4(-4)
= 9x² - 12x + 12x -16
= 9x² - 16

Now, let's simplify the right side of the equation:

(2x-4)² - 11
= (2x-4)(2x-4) - 11
= 4x² - 8x - 8x + 16 - 11
= 4x² - 16x + 5

Now, let's compare the two sides of the equation:

Left side = 9x² - 16
Right side = 4x² - 16x + 5

Since the two sides are not equal, the given equation is not true.