Answer: year 1948
Step-by-step explanation:
1900 is our t = 0
The population of Greenville can be written as:
G = 4000 + 100*t
the equation for Springfield can be written as:
S = 1000*(1.04)^t
we want to find the value of t that makes S(t) = G(t)
4000 + 100*t = 1000*(1.04)^t
(4000 + 100*t) = 1.04^t
4 + 0.1*t = 1.04^t
now, you can graph both of this equations (left side and right side) and see in wich value of t the graphs intersect eachother, or you also may use different values of t until the values are about the same for both sides, which is the thing i did with the equation:
4 = 1.04^t - 0.1*t
You will find that the correct value is t = 48
So we can assume that in year 1948 the populations will be about the same.