Which relationship between x and y in the equation shows a proportional relationship?

y= 12x
y= 12/x
y= 2x + 6
y= x/2 + 3

Do some research and find a city that has experienced population growth. determine its population on january 1st of a certain year. write an exponential function to represent the city’s population, y, based on the number of years that pass, x after a period of exponential growth. describe the variables and numbers that you used in your equation.