2021 Canadian junior team mathematics challenge down clues

Taking algebra two apex courses and need with these questions

Adam plans to choose a video game from the section of the store where everything is 75% off. he writes the expression d-0.75d to find the sale price of the game if the original price is d dollars. gena correctly writes another expression, 0.25d, that will also find the sale price of the game if the original price is d dollars. use the drop down menus to explain each part of adams and rena's expression

If 3x+8=3x+8 is it one solution or no solution