Python matplot

import matplotlib.pyplot as plt

a = 3b = 2c = 1
year = [x for x in range(-100, 100)]
pop  = [x*(a)+b for x in range(-100, 100)]
#pop  = [x*x*x*x*(a)+x*x*b+x*c + d for x in range(-100, 100)]
plt.plot(year,pop)
plt.show()