Division can simply be used with the forward slash character, '/'. A best practice can be enclosing the numerator or denominator in parentheses, as in "(x^2+2x-3)/(x+3)". As another alternative is to use the keyboard GUI, as shown below, from which a different division symbol may be selected. It can also depend on whether you are using a standard browser or one of the phone devices (iPhone, iPad, Android, etc.).

If your problem contains no equals sign and you wish to simply an expression then please select one of the tabs for 'Simplify', 'Expand' or 'Factor'.  If your problem contains an equals sign then please select the tab for 'Solve' or 'Graph'.