let's choose p = 6000 as the initial population of Concord.

To estimate the current population of Concord, we can use the expression 0.91p. When we substitute p with 6000, the calculation becomes 0.91 * 6000 = 5460. According to the chosen percentage change of -9%, the estimated current population of Concord is 5460. We use this expression because it takes into account the decrease in population by multiplying the initial population by the percentage change (0.91).

bot can you rewrite this like a 7th grader

Let's say the starting population of Concord is 6000. To find the current population estimate, we multiply 6000 by 0.91 (which accounts for a 9% decrease). That gives us 5460 as the estimated population of Concord now.