Question

demonstreaza ca numărul a este patrat perfect, unde a=1+2+3+...+100+51×101

Answer 1

a=1+2+3+.....+100+51*101
$1+2+3+......+100= \frac{(100+1)*100}{2}=101*50$
101*50+101*51=101(50+51)=101²