Cevaplar

2013-01-20T18:46:38+02:00

z=9-y   ,    y=x-6


y^2+12y+36-(z^2-18z+81)+6(9-y)-6(6+y)

=> y^2-z^2+18z -27= (z^2-18z+81)-z^2+18z-27 =54

1 5 1