Can anyone please help me with these math problems ? Thanks so much! :-)

Describe the end behavior of the function below. f(x)=(2/3)^x-2 a. as x increases, f(x) approaches infinity. b. as x decreases, f(x) approaches 2. c. as x increases, f(x) approaches -2. d. as x decreases, f(x) approaches negative infinity.

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18

What is the effect on the graph of the function f(x) = x2 when f(x) is changed to f(x) − 4?