2z²+az-5=0
a²-4*2*(-5)>0
a²+40>0
adevarat ∀a
fie a=3
b)
2z²+3z-5=0
Δ=9+40=49
√Δ=7
z1=(-3-7)/4=-10/4=-5/2
z2=(-3+7)/4=4/4=1
c)
opuse 5/2 si -1
f(z) =a(z-5/2)(z+1)
pt a=2
(2z-5)(z+1)=2z²-3z+5
fie m, numarul manualelor si a, numarul cartilorde literartura artistica
m/a=2/3
a=m+350
m/(m+350)=2/3
3m=2m+700
m=700
a=m+350=700+350=1050
total carti =a+m=1050+700=1750
