Fred buys candies. He buys 2 candies for a dollar and gets 3 candies free on every purchase

The equation for this would be 2d+3 where d is the money spent in dollars.

Step-by-step explanation:

I'm not sure if this is what you where looking for, if not perhaps elaborate on what the question is.

How I got this equation:

For every dollar he gets 2 candies. So you would multiply 2 by the number of dollars. (2d) He also gets 3 more candies per purchase, you add three regardless of money spent, so 3 is added. (+3)

Giving you: 2d+3

Can you finish the question at least?