Let's simplify the equation step by step:

(4.479 - 3x) / 0.06 + 6.4 = 80

First, divide (4.479 - 3x) by 0.06:

(4.479 - 3x) / 0.06 = 75

Now, multiply both sides by 0.06 to isolate (4.479 - 3x):

4.479 - 3x = 4.5

Subtract 4.479 from both sides:

-3x = 0.021

Divide by -3 to solve for x:

x = -0.007

Therefore, the solution to the equation is x = -0.007.