Which equation describes a parabola that opens up or down and whose vertex is at the point (h v)

Which of the following is the explicit rule for a geometric sequence defined a recursive formula of a -5a for which the first term is 23?

Simplify -4z+2y-y+-18z a.-22z+y b.-14z+2 c.3y+22z d. y +14z

Randy and trey take turns cleaning offices on the weekends. it takes randy at most 4 hours to clean the offices. it takes trey at most 6 hours to clean the offices. what is the greatest amount of time it would take them to clean the offices together? 2.4 hours 2.5 hours