Respuestas

2013-10-04T01:43:08+02:00
7P-56+67-P=2P-13
6P+11=2P-13
6P-2P=-13-11
4P=-24
P=-24/4
P=-6

10+N+N+N=26+39
10+3N=65
3N=65-10
3N=45
 N=15