Answer:
X=-3
Explanation
First of all, remove the parenthesis by distributing the value of the negative sign so it would be 4-x-1=6 , next find the like terms which is 4-1 is 3. so 3-x=6.
transpose the 3 to the other side so it would be -x=6-3
-x=3 divide both sides by -1. X=-3