Răspuns:
a) x^2=16=>x=4
b)2x^2=8=>x=2
c)x^2=-9=>x^2+9=0=>x=[-b+-radical(b-4*a*c)]/2*a
a=1; b=0; c=9
delta=-36
x=+-6i/2=>x=+-3i ∉ R => nu exista solutie reala
d)x^2=0=>x=0
e)2x^2-50=0=>2x^2=50=>x^2=25=>x=5
f)x^2-3x=0=>x(x-3)=0=>x1=0
x-3=0=>x2=3
g)2x^2+5x=0=>x(2x+5)=0=>x1=0
2x+5=0=>2x=-5=>x2=-5/2
