Răspuns:
Explicație pas cu pas:
Daca ecuatia are coeficienti reali ⇒ecuatia accepta si conjugata solutiei date
a) x1=4+2i x2=4-2i
x1+x2=8
x1x2=16-+4=10
x²-8x+10=0
b) (2-i)/(3+i)=(2-i)(3-i)/(9+1)=(6-5i+1)/10=(7-5i)/10
x1=7/10-i/2 x2=7/10+i/2
x1+x2=2·7/10=7/5
x1x2=(49/100+1/4)=(49+25)/100=74/100=37/50
x²-7x/5+37/50=0
c)(2-5i)(2+5i)=4+25=29
x²-841=0
