What is the vertex of this quadratic function?

f(x) = x2 – 4x – 5

Which describes the difference between the graph of f(x)=x^2 and g(x)=-(x^2-2)

Varies inversely with x. if y=8.5 when x=-1 find x when y=-1

Asandwich shop has 18 tables. each table seats up to 4 people. to find the greatest number of people that can be seated, you can solve p4 ≤ 18. which step is the best way to solve the inequality? plz asap i repeat plz