The two expressions that represent the retail price of cars is: Retail price = 1.21c and Retail price = c + 0.21c
Solution:
Given that,
Rick buys remote control cars to resell
He applies a markup of 21%
Let "c" be the original price of remote control cars
To find: Expression for retail price of car
We know that,
Retail price = original price + markup
Here, markup price = 21 % of original price
Markup price = 21 % of c
Therefore, substituting the given values we get,
Retail price = c + 21 % of c

This can also be expressed as,

Thus two expressions that represent the retail price of cars is: Retail price = 1.21c and Retail price = c + 0.21c