Răspuns:
[tex]5^{n^{2}+2n }=125\\5^{3}=125\\3=n^{2} +2n\\n^{2} +2n-3=0\\[/tex]
Δ=b²-4ac=4+12=16
n1=-b-√Δ/2a=-2-4/2=-6/2=-3/2
n2=-b+√Δ/2a=-2+4/2=2/2=1
⇒n∈{-3/2;1}
In a doua poza nu se vad bine cerintele!
Succes!:)))))
