1=-10 Hello. I'm currently a freshman in highschool and ran across this question and I forgot how to do it before. Can i get some help?​

What is the area of a pizza with a radius of 40 cm leave the answer in terms of π to find your exact answer 40π cm² 1600π cm² 800π cm² 80π cm² π=pi

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Hurry if the population of of an ant hill doubles every 10 days and there are currently 100 ants living in the ant hill what will the ant population be in 20 days