Respuesta :

apologiabiology
it's called a vinculum it signifies a repeeting group
no if a decimal has a vinculum over it it is a repeeting decimal so
1/3=0.333333333333333333333 or
  _
0.3 (3 has a vinculum over it)
 
or

0.345345345345345 is also
   ___
0.345 (345 has a vinculum over it)
it could be negative but
No, it means that the number it is over is repeating.