There are several reliable websites that offer solutions to textbook questions and problems for various subjects. Here are some of the most popular ones:

1. CrazyForStudy: CrazyForStudy is another website that offers solutions to textbook questions and problems for subjects like math, science, engineering, business, and more. It's a paid service that provides step-by-step textbook solutions, homework help, and online tutoring.
2. Chegg: Chegg is a well-known website that offers solutions to textbook questions and problems, study guides, and tutoring services for a wide range of subjects.
3. Khan Academy: Khan Academy provides free video tutorials and practice exercises for a wide range of subjects, including math, science, and humanities.
4. Slader: Slader is a free website that provides step-by-step solutions to textbook questions and problems for various subjects, including math, science, history, and English.
5. Course Hero: Course Hero is a paid service that offers textbook solutions, study guides, and tutoring services for a wide range of subjects.

The best website for you depends on your specific needs and preferences. Chegg and Course Hero are great options if you need additional study resources and tutoring services. Khan Academy and Slader are excellent if you're looking for free resources. CrazyForStudy is a good option if you're looking for a paid service that provides step-by-step textbook solutions and homework help for various subjects.

Chegg Study known for providing detailed textbook solutions, explanations, and Q&A support. It's a subscription-based Bitlife service with access to millions of solutions for a variety of subjects, including math, science, engineering, and business.