Please help me with this!

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

This is so hard and it’s for a test

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?