2) sol egale <=> Δ=0
Δ=[-(m-2)]²-4*1*4=0
Δ=m²-4m+4-16=m²-4m-12=0
Δ'=16+48=64
m1=6
m2=-2
3) 2012!/2010! -2011!/2010!=2011*2012-2011=2011(2012-1)=2011*2011=2011²=pp
4) nr div 5: 0,5,10,15,20,25,30,35,40,45,50 - 11 nr
nr nediv=toate-div= 51-11=40(caz fav)
caz pos=51 nr
P=fav/pos=40/51
6) AB||CD <=> mAB=mCD
mAB=(yB-yA)/(xB-xA)=5-7/2-4=-2/-2=1
mCD=(yD-yC)/(xD-xC)=2-4/1-3=-2/-2=1
mAB=mCD => AB||CD qed