Which expression is equivalent to 7a^2b+10a^2b^2+14a^2b^3

Suppose that the equations are:

The number of people increases exponentially as the temperature increases, so we can write this as a simple exponential relation.

N(T) = a0*r^(T)

Also, the number of people that leaves the park as the temperature increases are:

M(T) = a*T + b

So the combination of these equations can say the number of people that are arriving to the park minus the number of people that are leaving, this would be:

N(T) - M(T) = total change in the park population as the temperature changes = C(T)

C(T) = a0*r^(T) - a*T - b