Peter Schumer does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...

An equation is a mathematical statement showing that two expressions are equal. The two expressions are linked with an equals symbol (=). The unknown variable (often the letter \(x\)) can take any ...

The letter “x” often symbolizes something unknown, with an air of mystery that can be appealing. Illustration by Meilan Solly Even though “x” is one of the least-used letters in the English alphabet, ...