What is the Domain of the following logarithmic functions? 1) f(x) = log(3x – 21

What is the Domain of the following logarithmic functions?
1) f(x) = log(3x – 21)
2) f(x) = log(2x + 16)
3) f(x) = log2 (x – 2)
Perform the operations:
4) log2 4 + log4 2 =
5) log 1000 + ln e5 =
Solve the equation:
6) x2 = log 100 + 90
7) Make a paragraph about an application of the Logarithmic Function to the real life and its importance.
On all the exercises show your work step-by-step.