As x is the independient variable write y in terms of x (solve y):
[tex]x-y=3[/tex]
Subtract x in both sides of the equation:
[tex]\begin{gathered} x-x-y=-x+3 \\ -y=-x+3 \end{gathered}[/tex]
Multiply both sides of the equation by -1:
[tex]\begin{gathered} (-1)(-y)=(-1)(-x+3) \\ y=x-3 \end{gathered}[/tex]
Substitute the y by f(x) to write it in function notation:
[tex]f(x)=x-3[/tex]Answer: f(x)=x-3
