Respostas

2014-02-02T15:41:23-02:00
 (2/3 + 1/4) - (1/10 + 1/4)=[ (8 + 3)/12] + [(2 + 5)/20] = 11/12 + 7/20 = (55 + 21)/60 = 76/20 = 19/5