How do you tell wether the ratios form a proportion 8/24 5/15

Astrid spent $36 on new shoes. this was $12 less than twice what she spent on a new skirt. part a: which equation would solve for how much she spent on the skirt? part b: solve the equation in the workspace provided below. how much did astrid spend on her skirt?

How do newtons third law of motion demonstrates on a rollar coster

Ineed with question three. i don't understand how i'm supposed to achieve 3 marks.