Find the allowable height for the hypotenuse if the hypotenuse catheters are 4 cm and 9 cm

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

How to do this , and can some one explain

Rewrite so the subject can be y in the formula d=m-y/y+n