Răspuns:
Explicație pas cu pas:
a) notam x²=t
3t²-4t+1=0
t1,2=2±√(4-3)/3 t1=3/3=1 t2=1/3
x²=1 x1,2=±1
x²=1/3 x3,4=±√3/3
b)5t²-4t-1=0
t1,2=2±√(4+5)/5=2±3/5
t1=1 t2=-1/5
x²=1 x1,2=±1
t2=-1/5 nu are solutii reale
c)t²+10t+169=0
t1,2=-5±√25-169 nu are solutii reale Δ<0
