Welp now I need help with math sooo does anyone know how to do this, it’s geometry

The function f(x) = 14,600(1.1)* represents the population of a town x years after it was established. what was the original population of the town?

Twelve less than a number is at most 20

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.