Answer:
To expand and simplify the expression (4x+6)(8x+9)(12x-4), we will use the distributive property. First, we multiply the first two terms together:
(4x+6)(8x+9) = 32x2 + 48x + 54
Next, we multiply the last two terms together:
(8x+9)(12x-4) = 96x2 - 36x - 36
Finally, we add the two expressions together:
32x2 + 48x + 54 + 96x2 - 36x - 36 = 128x2 + 12x + 18
Therefore, the simplified expression is 128x2 + 12x + 18.