Respuesta :
Long,detailed solution, we make the denominator the same first
5/12 , times 20 to both numerator and denominator, 100/240
3/20 , times 12 to both numerator and denominator = 36/240
so 36/240 - 100/240 = -64/240 = -4/15
5/12 , times 20 to both numerator and denominator, 100/240
3/20 , times 12 to both numerator and denominator = 36/240
so 36/240 - 100/240 = -64/240 = -4/15