Answer:
Hence, the normal price of each cookie= $ 1.15.
Step-by-step explanation:
Cookies are on sale!
Today each cookie costs  $0.75  less than the normal price.
So let c be the normal price of one cookie.
Hence, today 1 cookie will cost= $ (c-0.75)
Right now if you buy  7 of them it will only cost you $2.80!
Hence,
cost of 7 cookie= 7×(c-0.75)
This means that:
7×(c-0.75)=2.80
i.e.  7c-7×0.75=2.80
⇒   7c-5.25=2.80
⇒  7c=0.80+5.25
⇒  7c=8.05
dividing both side by 7 we get:
c=1.15
Hence, the normal price of each cookie= $ 1.15.
