Réponses

2014-01-20T17:56:12+01:00
N(n+1) = n² + 2(n+1)
n² +n = n² +2n +2
n - 2n = 2
-n = 2
n = -2
n(n+1) = n²+2(n+1) revient à n² + n = n²+2n +1 soit n²-n² +n -2n = 1 donc -n = 1 alors n = -1
2(n+1) = 2n + 2
Mille excuses n=-2
:)
2014-01-20T17:58:25+01:00
Bonsoir

n(n+1) = n² +2(n+1)
n² +n = n² +2n +2
n² -n² +n -2n = 2
-n = 2
n = -2