Question

Sa se rezolve in multimea nr intregi ecuatia:  $x^{2} -5x+5 \leq 1$

Answer 1

x²-5x+5≤1
x²-5x+4≤0
x₁=4, x₂=1
functia este negativa intre radacini deci x∈[1,4]

Answer 2

(x+1)! /(x+1-2)!=6
(x+1)! /(x-1)!=6
(x-1)!x(x+1)/(x-1)!=6 (se simplifica in fractie (x-1)!)
x(x+1)=6
x^2+x-6=0

Δ=1-24
Δ=-23⇒ ∉ R