Anybody help please ! Step by step

Your answer is -6.
Hope my answer is helpful to you. Stay blessed .
[tex]\\ \large\sf\longmapsto {27}^{x} = {9}^{x - 3} \\ \\ \large\sf\longmapsto ( {3}^{3} ) {}^{x} = ({3}^{2} ) {}^{x - 3} \\ \\ \large\sf\longmapsto 3 {}^{3x} = 3 {}^{2(x - 3)} \\ \\ \large\sf\longmapsto {3}^{3x} = 3 {}^{2x - 6} \\ \\ \large\sf\longmapsto 3x = 2x - 6 \\ \\ \large\sf\longmapsto 3x - 2x = - 6 \\ \\ \large\sf\longmapsto x = - 6[/tex]