Completing the square. (+25 points+!) Someone please help:)

Option 1: $30 an hour plus a nonrefundable deposit of $50 option 2: $20 an hour plus a nonrefundable deposit of $75 kyle is renting a jetski for the day. if he can rent the jetski in one hour increments, what is the minimum number of hours must he rent the jetski for option 2 to be a better deal then option 1?

Awater tank holds 18000 gallons. how long will it take for the water level to reach 6000 gallons if the water is used at anaverage rate of 450 gallons per day

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.