math
posted by Anonymous .
The number of streetlights in a town is growing linearly. Four months ago (n = 0)
there were 130 lights. Now (n = 4) there are 146 lights. If this trend continues,
a. Find an explicit formula for the number of lights in month n
b. How many months will it take to reach 200 lights?

z = 130+4n
z=200 when n=17.5