[tex]\qquad\qquad\huge\underline{{\sf Answer}}[/tex]
Here we go ~
[tex]\qquad \tt \dashrightarrow \:81x - 27x = 9[/tex]
[tex]\qquad \tt \dashrightarrow \:9(9x - 3x )= 9[/tex]
[tex]\qquad \tt \dashrightarrow \:(9x - 3x )= 1[/tex]
[tex]\qquad \tt \dashrightarrow \:6x = 1[/tex]
[tex]\qquad \tt \dashrightarrow \:x = \cfrac{1}{6} [/tex]
