Please help with my math homework

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?

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

Roger and natalie travel in similar cars. roger's car drives the two miles to school in 7.5 minutes. natalie drives the same distance in the opposite direction but in only 6.5 minutes. what is true of their velocities?