Question

Dovediti ca numerele urmatoare sunt patrate perfecte:

a) 100
b) 9^7
c) 2x (1+2+3+...+2005)-2005.

Dau coroana la primul raspuns corect.

Answer 1

a) 100 = 10 * 10 = $10^2$
b) $9^7 = (3^2)^7 = (3^7)^2$
c) 2 * (1+2+3+...+2005) - 2005 = 2 * 2005 * 2006 : 2 - 2005 = 2005(2006 - 2005) = 2005 * 2005 = $2005^2$