Respuesta :
find a common denominator
the common denominator of 7 and 3 is 21
2/21 - 3/21
change the numerator
14/21 - 9/21 =5/21
the common denominator of 7 and 3 is 21
2/21 - 3/21
change the numerator
14/21 - 9/21 =5/21