Răspunsuri

2014-02-24T16:34:01+02:00
Suma=678
b=a+1
c=a+2
d=a+3

1+2+3=6
678-6=672
672:4=168 ( a )
168+1=169 (b)
168+2=170(c)
168+3=171(d)

9 4 9