Question

(f • g)=82 ( circle is open) f(x)= log3 (x+5) g(x)=log3 (x-1)

Answer 1

the 3 is a base

Answer 2

This is a composite function.
f circle g means f composed with g. f(g(x))

f(x)= log3 (x+5) // g(x)=log3 (x-1)

Than f(log3(x-1) --> log3(log3(x+5)-1)
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Answer 3

log3(log3(x+5)-1) = 82

Rewrite
solve for x -->
3^82 = log3(x+5)-1
3^82+1 = log3(x+5)
1.3 x 10^39 = log3(x+5)
3^(1.3x10^39) = x+5

x= 3^(1.3x10^39) - 5

x= approx. 1.3 x 10^(39)