a rectangle has height and width changing in such a way that the area remains constant 3 square feet. at the instant the height is 3 feet, the height is changing at a rate of 6 feet/minute. find the rate of change of the width (in feet/min) at that instant.

It depends on the subject for me. some exams are easier than others so i usually go through it and answer questions i know based on my general knowledge, then double check after. going through the lesson can a lot  because the exams can be  very lesson-specific, but sometimes they are ridiculously long so a lot of people don't take the time. i did find that, when i went through the lessons, i was making 100's on my exams vs strictly using + the internet and  i make 90's.