How can you tell that a website is valid and reliable?

If there is an about page where it tells whom made the website, as well as a copyright 2016 on the bottom of the page. This basically means the website is useful and updated by the creators. Another factor which the site doesnt always need but if it has an https at the beginning of the url then it should be good and valid because that means the site is secured. Also factor in the sections where articles are present, if they have a date and an author towards the bottom or top of the article, then it can be trusted as well. Theres a lot more you can look for in a site and validating if it is an okay site but these are a few examples. Hope this helped!:)

These are very for instance for math pemdas parenthesis, exponents, multiplication, division, addition, subtraction without that i would never be able to remember what to do first with it i can remember.