Question

Află valoarea lui N [(n+2) (n+3)+25 ]:9+11=20

Answer 1

((n+2)(n+3)+25):9=20-11
(n+2)(n+3)+25=9*9
n^2+3n+2n+6=81-25
n^2+5n+6=56
n^2+5n+6-56=0
n^2+5n-50=0
Δ=b^2-4ac
Δ=5^2-4*1*(-50)
Δ=25+200
Δ=225
n₁=(-b+√Δ)/2a=(-5+15)/2=10/2=5
n₂=(-b-√Δ)/2a=(-5-15)/2= -20/2= -10