To solve for x, we can start by simplifying the equation:

3.4x + 0.65 = 0.9x - 25.6

First, let's subtract 0.9x from both sides to isolate the x terms on one side:

3.4x - 0.9x + 0.65 = -25.6

Simplify the left side of the equation:

2.5x + 0.65 = -25.6

Now, let's subtract 0.65 from both sides:

2.5x = -26.25

Finally, we can solve for x by dividing by 2.5:

x = -26.25 / 2.5
x = -10.5

Therefore, the solution to the equation is x = -10.5.