Answer:
x = 3
Step-by-step explanation:
[tex] {3}^{(x + 1)} + {3}^{x} = 108 \\ \\ {3}^{x} .3 + {3}^{x} = 108 \\ \\ {3}^{x} (3 + 1) = 108 \\ \\ {3}^{x} (4 )= 108 \\ \\ {3}^{x} = \frac{108}{4} \\ \\ {3}^{x} = 27 \\ \\ {3}^{x} = {3}^{3} \\ \\ \implies x = 3[/tex]