Question

Sa se rezolve ecuatia A de n luate cate 2 egal 12, n apartine lui N. Multumesc!

Answer 1

$\frac{n!}{(n-2)!}$=12
$\frac{(n-2)!*(n-1)*n}{(n-2)!}$=12
(n-1)*n=12
n²-n-12=0
Δ=1+24=25
n1=$\frac{1+5}{2}$=3
n2=$\frac{1-5}{2}$ <0 nu e bun
Solutia e 3