To determine the equation of the normal price, set the equation.
Total = t; cookie = c; normal = n; original (price)= o
t = n(c)
Right now, if you buy 7 of them, it will cost 2.80
2.80 = n(7)
Isolate the n. Divide 7 from both sides
(2.80)/7 = (7n)/7
n = 2.80/7
n = 0.40
normal price is 40 cents.
You are finding the original price = o
o = 0.40 + 0.75
o = 1.15
Equation for each cookie original price:
t = o(c)
original price: $1.15
~
