Help pls :( im so close to having a c

Answer:
x=2
Step-by-step explanation:
First we can find out what [tex](\frac{1}{81} )^{2} [/tex] in terms of 9 is...
[tex]\frac{1}{81} ^{2}=\frac{1^{2}}{81^{2}} =\frac{1}{81^{2}} =\frac{1}{9^{4}} [/tex]
This means we need 3x-10 to be equivalent to -4 as [tex]9^{-4}[/tex] is equivalent to [tex]\frac{1}{9^{4}} [/tex].
3x-10=-4
Add 10 to both sides
3x=6
Divide both sides by 3
x=2