Answer:
-3
Step-by-step explanation:
The given rational expression is [tex]\frac{12-x}{x-6}[/tex]
In order to find the value of the expression when x = 3, substitute x=3 in this expression.
[tex]\frac{12-3}{3-6}[/tex]
On simplifying numerator and denominator, we get
[tex]\frac{9}{-3}[/tex]
This fraction can be simplified and we get
[tex]-3[/tex]
Hence, the value of the expression at x =3 is -3
