Answer:
[tex]a=\frac{8}{9}[/tex]
Step-by-step explanation:
[tex]3^x-3x^{x-2} =a3^x[/tex]
Divide both sides by [tex]3^x[/tex]:
[tex]3^{x-x}-3^{x-x-2}=a[/tex]
Simplify:
[tex]3^0-3^{-2}=a\\a=1-\frac{1}{9} \\a=\frac{8}{9}[/tex]