Explain how using basic facts can help you find 10x20x30x40 mentally

You can model the population of a certain city between 1955-2000 by the radical function p(x)=55,000 sqrt x-1945. using this model, in which year was the population of that city 220,000

45 was divided by a power of ten to get 4.5. what power of ten was it divided by? people 4.5

State one method by which you can recognize a perfect square trinomial.