How do i solve qudratic equations with factions, like this one: x²-5= 0

Aretha wanted to gather data about the cost of local bowling leagues in her area. she plotted the data and determined that the average bowling league costs consist of a one-time registration fee and a monthly fee modeled by the equation y = 15x + 20. identify and interpret the y-intercept in this model. the y-intercept is 20. this is the cost per month. the y-intercept is 20. this is the cost of registration. the y-intercept is 15. this is the cost of registration. the y-intercept is 15. this is the cost per month.

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)

Jim had 15 minutes to do 5 laps around his school what would his time be