Question

Virginia's parents gave her money to put in her cafeteria account at the beginning of the school year. the function f (s) = 60 – 2.5s describes the amount remaining in her account after she had purchased lunch for s school days. how many days had she eaten in the lunchroom when her account balance was $27.50?

Answer 1

60- 2.50s =27.50 so s= 60-27.50/2.50= 32.50/2.50 =13 so Virginia ate lunch for 13 days @2.50 per day. 

check 2.50 x 13= 32.50 and subtract from 60 you will have 27.50 left

Answer 2

Given:f(s) = 60 – 2.5sset f(s) to 27.50 and solve for s:27.50 = 60 – 2.5s-32.5 = –2.5s32.5 = 2.5s32.5/2.5 = s13 days = s

Not 100% sure kay~