2.Rezolvati in R ecuatia combinari de 5x-2 luate cate 2=3

Răspuns :

[tex] C^2_{5x-2} =3;DVA:5x-2 \geq 2 \\ \frac{(5x-2)!}{2!(5x-2-2)!}=3 \\ (5x-3)(5x-2)=6 \\ 25 x^{2} -25x=0 \\ 25x(x-1)=0 \\ x=0;x=1 [/tex]
x=0∉DVA
s={1}