Answer:
c = 7p
Step-by-step explanation:
If 1 person buys the platter, the bill is c = 1 × $7.
If 2 people buy the platter, the bill is c = 2 × $7.
If 3 people buy the platter, the bill is c = 3 × $7.
(Do you see the pattern yet?)
If "p" people buy the platter, the bill is c = p × $7.
We ususally say "c is in dollars" and drop the "$" sign from the equation. When p is multiplied by 7, we conventionally write it as 7p.
... c = 7p