x-3,5=-2,1

To solve the equation \( x - 3.5 = -2.1 \), you need to isolate \( x \).

1. Start with the equation: \[ x - 3.5 = -2.1 \]

2. Add \( 3.5 \) to both sides of the equation to isolate \( x \): \[ x = -2.1 + 3.5 \]

3. Calculate the right side: \[ -2.1 + 3.5 = 1.4 \]

Thus, the solution is: \[ x = 1.4 \]