Answer:
The required equation is:

The price p (in dollars) of the stock yesterday was $75.72
Explanation:
Consider the provided information.
A stock has a price of $68.54. This is $7.18 less than the price of the stock yesterday.
Let the price of the stock yesterday is represented by p.
Therefore, the required equation is:

Now solve the above equation for p.


Hence, the price p (in dollars) of the stock yesterday was $75.72