Let's say that the price of each normal cookie is n.
The equation would then be 7(n - .75)=2.80.
Use distributive property, getting 7n - 5.25=2.80.
Add 5.25 to each side of the equation, getting 7n=8.05.
Divide 7 from both sides of the equation, getting n=1.15.
16-9=7
I am pretty sure that is what yo are asking for right?
It's 67/100 because a percent is out of 100 which is already simplified
Ratios don't have to be "per" something, while rates are "per" something.
Ratios compare 2 or more values, as well as rates.