Answer:
g(x) = 3f(x)
Step-by-step explanation:
Stretching vertically by a factor of 3 multiplies every function value by 3. Thus ...
... g(x) = 3f(x)
_____
Your given equation makes no sense unless we add some parentheses.
For ...
... f(x) = 8×3^(x-2) +2
... g(x) = 3f(x) = 3×(8×3^(x-2) +2)
... g(x) = 8×3^(x-1) +6