Răspuns:
Explicație pas cu pas:
A = 1 + 2 + ...+ 10 + 10*(2^0 + 2^3 + 2^4 + 2^5)
= 10*(1 + 10)/2 + 10*(1 + 8 + 16 + 32) = 10*11/2 + 10*57 = 55 + 570 = 625 = 25^2 patrat perfect
√A = √625 = 25
______________
C = 1 + 3 + 5 + ...+ (2n - 1)
2n - 1 = 1 + (m - 1)*2 = 1 + 2m - 2 = 2m - 1
2n = 2m
m = n
suma are m = n termeni
C = m*(1 + 2n - 1)/2 = n*2n/2 = n^2 patrat perfect
√C = √n^2 = n
