To solve this equation, we first need to expand the expression using the distributive property:

(5x - 8)(3x + 18)(5.6 - 0.8x) = (5x - 8)(3x + 18)(5.6) - (5x - 8)(3x + 18)(0.8x)

Expanding further:

= (15.6x^2 + 89.6x - 26.4) - (12x^2 + 68x - 19.2)

Next, combine like terms:

15.6x^2 + 89.6x - 26.4 - 12x^2 - 68x + 19.2 = 3.6x^2 + 21.6x - 7.2

So the equation becomes:

3.6x^2 + 21.6x - 7.2 = 0

Now, we can solve this quadratic equation by factoring, using the quadratic formula, or by completing the square.