Question

tim so tu nhien n sao cho 

n*[n-1]=6

 

Answer 1

n.(n-1)=6=3.2

=>n.(n-1)=3.(3-1)

=>n=3

Answer 2

n.(n+1)=6

n²+n - 6=0

n²-2n+3n-6=0

n(n-2)+3(n-2)=0

(n+3)(n-2)=0

nên n+3=0=>n=-3

 hoặc n-2=0=>n=2