You can use logarithms: Log9(27) which will give you the value of x X= 1.5

[latex]9^x=27\\\\(3^2)^x=3^3\\\\3^{2\cdot x}=3^3\\\\3^{2x}=3^3\iff 2x=3\ \ \ /:2\Rightarrow x=1.5[/latex]