I need help ASAP! (corrects answers will gets a thanks and 5 stars)

Ateam of runners is needed to run a 1 2 -mile relay race. if each runner must run 1 4 mile, how many runners will be needed?

If f(x)=3 over x+2 - square root x-3 then f(7)=

Afitness center has 2 membership plans one has a low dollar sign up fee of 15 dollars and costs 38 dollars per month to join. a second plan has a higher sign up fee of 78 dollars but a lower monthly fee of 31 dollars for what number of days of the month is the coat the same