plot of family of functions

how to plot multiple functions? for every value of a function with a variable wich represents real numbers from -inf to +inf, i want the graph for a function wich has the same variable but is multiplied by a constant( wich is the value of first function) a=12(1-e^(-0.7/x)) for each value( or at least for theier integer values) of a i want the graph of b b=a*e^(-0.7/x)

. so i will have as many graph as integer value of a Thanks