Respuestas

2011-11-29T17:05:48+01:00

3 x 4 - 15 : (12 + 4 x (2 - 7) + 5) = 

= 12 - 15: (12 + 4 x (-5) + 5) = 

= 12 - 15 : (12 - 20 +5) =

= 12 - 15 : (-3) = 

= 12 - (-5) =

= 17