Sketch graphs of the following exponential function. For each, find the value of x where it is

Question:

Sketch graphs of the following exponential function. For each, find the value of x where it is equal to 7.0. For the increasing functions, find the doubling time, and for the decreasing functions, find the half-life. For what value of x is the value of the function 3.5? For what value of x is the value of the function 14.0?
e-3x