Question

Va rog.. am nevoie pana maine !!!!

Answer 1

[tex]A_{x}^2=7\\ \frac{x!}{(x-2)!} =7\\ \frac{(x-2)!(x-1)x}{(x-2)!} =7\\ (x-1)x=7\\ x^2-x-7=0\\ \triangle=1+4\cdot7=29\\ x_{1/2}= \frac{1\pm \sqrt{29} }{2} \notin\ \ N[/tex]
Deducem ca ecuatia nu admite solutii.