Answer:
![x=0](https://img.qammunity.org/2021/formulas/mathematics/high-school/6enp4x8l6ye502n229t5aopx507rpkpsln.png)
Explanation:
Evaluate all the arithmetic first, and then remember absolute value equations have two possible ways to go (+ and -).
You can see how I split them on the 3rd line, later demonstrating how the 2nd one is invalid.
![|3-x|-x+1=4\\\\|3-x|-x=3\\\\3-x-x=3\\-(3-x)-x=3\\\\3-2x=3\\-3+x-x=3\\\\-2x=0\\-3\\eq 3\\\\x=0\\-3\\eq 3\\](https://img.qammunity.org/2021/formulas/mathematics/middle-school/awfs2n5tdolplzrwzyj06o66zkwwo27q72.png)
Therefore, the solution is
![x=0](https://img.qammunity.org/2021/formulas/mathematics/high-school/6enp4x8l6ye502n229t5aopx507rpkpsln.png)