please tell me if these answers are correct

hi.

1- log(x+8) -logx=log(8+x)

my answer is x=1

2- log square root of X^2-4

_________________

(x-1) ^3

all this fraction goes into parenthesis.

my answer is inx+1/2in(x^2-4) -1/3 in (x-1)

3= e^3x+2=1

my answer is x = -2/3

4 - a business that develops a product in high demand calculates its revenue by the function r(t) = Ro2^t where Ro represents the initial revenue and R(t) represents the revenue after t years, how much revenue is being generated after 3 years if the company initial revenue is 3 millions? here my answer is 24.000000

thank you.