Answer:
A) 40 + d
B) 45 days
Explanation:
A)
total cost = (cost of the air conditioner itself) + (money charged per day)*(days)
cost of air conditioner itself = $40
money charged per day = $1
days = d
40 + 1*d
= 40 + d
B)
total cost = 40 + d
total cost = $85
85 = 40 + d
45 = d
Time used the air conditioner for 45 days.