Is the following a function? and I need to know why is it

Describe the domain and range of y=2(3)^x-2+5

In the field of thermodynamics, rankine is the unit used to measure temperature. one can convert temperature from celsius into rankine using the formula , what is the temperature in celsius corresponding to r degrees rankine? a. 9/5(c - 273) b. 9/5(c + 273) c. 5/9( c - 273) d. 5/9( c + 273)

If f(x) = 4x - 3 and g(x) = x + 4, find (f - g) (x)