How to simplify the expression )?

What is the sum of these mixed numbers 2 1/8 + 4 3/8

Aflute is on sale for 20% off. including the discount and 8% tax, the sales price is $216.

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