Final answer:
The differential equation describing the number of people infected by the zombie plague is dX/dt = kX, where X represents the number of infected people and k is the proportionality constant. The units for k in the differential equation are people per time. The general solution to this equation is X(t) = Ce^(kt), where e is the base of the natural logarithm. The units for k in the solution are 1/time.
Step-by-step explanation:
The differential equation describing the number of people infected by the zombie plague is dX/dt = kX, where X represents the number of infected people and k is the proportionality constant. The units for k in the differential equation are people per time.
To find the general solution to this equation, we can separate the variables and integrate both sides: 1/X dX = k dt. Integrating, we get ln|X| = kt + C where C is the constant of integration.
The general solution is X(t) = Ce^(kt), where e is the base of the natural logarithm. The units for k in the solution are 1/time.