A laptop was sold at a 20% increase in cost price at the beginning, and then it was sold at a 15% discount due to market reasons. After the price reduction, each laptop sold for 5100 yuan. Did you lose or make a profit when you sold one of these laptops? How much did you lose or make?

A laptop was sold at a 20% increase in cost price at the beginning, and then it was sold at a 15% discount due to market reasons. After the price reduction, each laptop sold for 5100 yuan. Did you lose or make a profit when you sold one of these laptops? How much did you lose or make?

5100 ^ [(1 + 20%) × 85%] = 5100 ^ [120% × 85%], = 5100 ^ [102%, = 5000 (yuan). 5100-5000 = 100 (yuan). A: this kind of laptop makes a profit of 100 yuan by selling one