Question 152366
Asking for the domain is the same as asking: "What x values are defined for this function?" So, for g(x)=5^x, can you think of any number where x is not defined?

I can't. The domain is the set of all real numbers.

Even though it's not asked for, you can think of range in similar terms: "What y values are defined for this function?" So, for y=5^x, can you see any y values that are not defined?

I can. y will always be greater than 0. The range is the set of all real numbers greater than 0. Note that 0 would not be included because 5^x is always greater than 0.