Let's simplify the given equation step by step:

5 + 6 - 3(2 - 0.4x) = 0.4(4x + 1)

5 + 6 - 3(2) - 3(-0.4x) = 1.6x + 0.4

5 + 6 - 6 + 1.2x = 1.6x + 0.4

5 + 6 - 6 - 1.6x = 1.6x + 0.4

5 + 0 - 1.6x = 1.6x + 0.4

5 - 1.6x = 1.6x + 0.4

Now, let's solve for x:

Add 1.6x to both sides:

5 - 1.6x + 1.6x = 1.6x + 0.4 + 1.6x
5 = 3.2x + 0.4

Subtract 0.4 from both sides:

5 - 0.4 = 3.2x + 0.4 - 0.4
4.6 = 3.2x

Divide by 3.2 on both sides:

4.6 / 3.2 = 3.2x / 3.2
1.4375 = x

Therefore, the solution to the equation is x = 1.4375.