Answer:
x=5
Step-by-step explanation:
(1/81)^x=(243)^x-9
(1/3^4)=3^5(x-9)
3^-4x=3^5(x-9)
-4x=5(x-9)
-4x=5x-45
-4x-5x=-45
-9x=-45
1:3
you can simplify both factors by 3 so 3:9 will be 1:3
1000000000000000000p000000000000
If this is an option, it should be Similar Triangles.