Plz will give maxium points if right

Bradley hikes 12 miles in 3 hours. in relation to bradley’s hike, which statement describes the expression

Samantha is growing a garden in her back yard. she spend $90 setting up the garden bed and buying the proper garden supplies. in addition, each seed she plants cost $0.25. a. write the function f(x) that represents samantha's total cost on her garden. b. explain what x represents. c. explain what f(x) represents. d. if samantha plants 55 seeds, how much did she spend in total?

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?