Svp aidez moi ex 2 et 3

exercice 2

(n-1)² +n² = (n+1)²

n²-2n+1+n² = n²+2n+1

2n²-2n+1-n²-2n-1 =0

n²-4n = 0

n(n-4) =0

n =0            n-4 =0

n =0              n = 4

solution (0.4)

3,4,5

3²+4² = 5²

9+16 =25

volila

exercice 3

e =( n+1)² -(n-1)²

e = n²+2n+1 -(n²-2n+1)

e = n²+2n+1-n²+2n-1

e =4n

factoriser

(n+1)²-(n-1)²

(n+1-n+1)(n+1+n-1)

2(2n)

4n