Answer: If the store sold 25% of its books during the holiday, that means it has 75% of its books left in stock after the holiday. Let's represent the original number of books with the variable "x".
So, if 75% of x is equal to 600 books, we can write an equation:
0.75x = 600
To solve for x, we can divide both sides by 0.75:
x = 600 / 0.75
x = 800
Therefore, the store had 800 books before the holiday.
Explanation: