Answer:
x = 11
Step-by-step explanation:
Given
[tex]3^{x-7}[/tex] + 4 = 85 ( subtract 4 from both sides
[tex]3^{x-7}[/tex] = 81
[tex]3^{x-7}[/tex] = [tex]3^{4}[/tex]
Since the bases on both sides are equal, both 3 then equate the exponents
x - 7 = 4 ( add 7 to both sides )
x = 11
