Question

n=1+2+3+.....+109-55•54 arătați ca e patrat perfect varog rapid

Answer 1

$n = 110 \times 109 \div 2 - 55 \times 54$
$n = 55 \times 109 - 55 \times 54$
$n = 55 \times (109 - 54)$
$n = 55 \times 55$
$n = {55}^{2}$
=> n = patrat perfect