Respuestas

2013-09-25T03:49:14+02:00
★42 + 4/13 - 13 + 2/7 = 550/13 - 89/7 = 2693/91
★25 + 4/5 - 15 + 3/20 =  129/5 - 297/20 = 229/20
★4 + 3/13 - 1 + 1/7 = 55/13 - 8/7 = 281/91
★24 - 2 . 1/4 = 24 - 1/2 = 47/2
★24 - 8 . 2/3 = 24 - 16/3 = 56/3

A = 16 - 2 . 3100/500 = 16 - 60 = - 44