1-1,7х-(0,8х+2)=3,4

To solve the equation \(1 - 1.7x - (0.8x + 2) = 3.4\), let's first simplify it step by step.

1. Distribute the negative sign across the parentheses: \[ 1 - 1.7x - 0.8x - 2 = 3.4 \]

2. Combine like terms: \[ 1 - 2 - (1.7x + 0.8x) = 3.4 \] This simplifies to: \[ -1 - 2.5x = 3.4 \]

3. Now, add 1 to both sides to isolate the term with \(x\): \[ -2.5x = 3.4 + 1 \] \[ -2.5x = 4.4 \]

4. Divide both sides by -2.5 to solve for \(x\): \[ x = \frac{4.4}{-2.5} \] \[ x = -1.76 \]

So, the solution to the equation is: \[ \boxed{-1.76} \]