Question

Calculeaza suma:
s=1^2+2^2+3^2+...+5^2

Answer 1

1²+2²+...+n²= n(n+1)(2n+1)/6.

n=5=> 1²+2²+...+5²=5(5+1)(2*5+1)/6=5*6*11/6=55

Answer 2

S = 1 ^ 2 + 2 ^ 2 + 3 ^ 2 + 4 ^ 2 + 5 ^ 2
S = 1 + 4 + 9 + 16 + 25
S = 5 + 9 + 16 + 25
S = 14 + 16 + 25
S = 30 + 25
S = 55