Apopulation of 550 cheetahs decreases by 10% per year. how many cheetahs will there be in the population after 10 years

Select a graph that have an equation with a < 0

Let hh represent the number of hummingbirds and ss represent the number of sunbirds that must pollinate the colony so it can survive until next year. 6h+4s > 746h+4s> 74 this year, 88 hummingbirds pollinated the colony. what is the least number of sunbirds that must pollinate the colony to ensure that it will survive until next year?

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?