Sagot :
Bonsoir !
A = (n+1)²-(n-1)²
A = (n² +1 +2n)-(n²+1-2n)
A = n²+1+2n-n²-1+2n
A = 4n
S = {4n}
A = (n+1)²-(n-1)²
A = (n² +1 +2n)-(n²+1-2n)
A = n²+1+2n-n²-1+2n
A = 4n
S = {4n}
Bonsoir
( n + 1 ) ² - ( n - 1 ) ²
C'est la différence de 2 carrés
(n +1 +n -1)( n +1 -n +1)
2(2n)
( n + 1 ) ² - ( n - 1 ) ²
C'est la différence de 2 carrés
(n +1 +n -1)( n +1 -n +1)
2(2n)