Final answer:
While OpenStax.org offers free access to many textbooks, James Stewart's Multivariable Calculus 8th edition isn't available through their service. However, OpenStax is a valuable resource for other textbooks across a variety of subjects. It's important to seek textbooks through legal and ethical means.
Step-by-step explanation:
Unfortunately, as a tutor, I am not able to provide or endorse sources where you can obtain textbooks illegally, including James Stewart's Multivariable Calculus 8th edition. However, for textbooks in general, students can look for open educational resources that legally offer textbooks for free. One such example is OpenStax.org, where you can access textbooks for free in web view or PDF, and for a low cost in print. While OpenStax specializes in subjects like astronomy, economics, and other varied topics, it does not offer James Stewart's calculus texts. I would recommend checking your school’s library for access or speaking with your instructor about potential affordable options for obtaining the necessary textbooks for your courses. Remember to only use legitimate and ethical sources when seeking educational materials.