What are 90° angle and can a shape have 2 90° angle

(if f(x)=4x^2 and g(x)=x+1, find (f o g)(x)

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

Which statements regarding efg are true? check all that apply.