a) delta=-4*6*0.5<0 ---nu are solutii reale
b)delta=169-4*3*-10=169+120=289(17*17)---x1=-13+17/6=4/6=2/3
c)25x²+10x+1=0,delta=100-4*25=0----
orice x ∈ R este solutie a ecutiei
d)delta=0.2*0.2=0.04,x1=-0.2+0.2/10=0,x2=-0.4/10=-0.04
e)delta=36-4*5=16,x1=6+4/10=1,x2=6-4/10=1/5
9x²-6x+1=0,delta=36-36=0---la fel ca la c)
