If you're looking for something to replace Gauth, Wolfram|Alpha is another good option. This computational knowledge engine offers step-by-step solutions and detailed explanations in a broad range of subjects, including math, science and more. It also has abilities like image processing, file upload and support for lots of web apps, so it's good for homework and professional work, too.
Another alternative is Homework AI. The service offers immediate answers and explanations for math and science homework problems, and an optional AI Essay Writer that can write essays in your own voice. It has a range of pricing levels to accommodate different needs, so students can find a level of help that's affordable.
If you're looking for something more narrowly focused on math, SnapXam offers detailed step-by-step solutions to a lot of math problems, including algebra, calculus and trigonometry. It also has a math worksheet generator and a step checker, so it's good for homework and studying. Its subscription plans let you use it on multiple devices.
Last, Chegg is a broad-based service that offers 24/7 homework help, textbook rentals and tools for writing and exam prep. Its feature set is pretty broad, including the Chegg Math Solver and plagiarism checker, so it's a good option for students who want help with a lot of different aspects of their academic life.