As I understand, you need to write an equation that relates [tex]t \ and \ y[/tex]. This problem will be solved using equations. The problem states:
Nick bought t candies and divided them equally between his y friends and me. Each of us got 7 candies.
From this statement, we know that:
t: Number of candies Nick bought.
y: Number of friends.
Since I am included in this problem, the number of people involved here can be expressed as:
[tex]y+1[/tex]
Since each of us got 7 candies, then it is true that:
[tex]\frac{t}{y+1}=7 \\ \\ t=7(y+1)[/tex]
So t (number of candies) is a function of y(number of friends).