First problem.
The function is f(x) = 3^x.
The base, b, is 3 since 3 is raised to power x.
The question is what value of x used in 3^x makes the expression 3^x equal to 3?
Look at the graph, and find the point that has y-value 3.
Which x-value does that point have?
The point is (1, 3), and the x-value is 1.
Second question.
The question is similar to the question above using a different exponential function.
(1/4)^1 = 1/4, so the answer is x = 1
