Question

calculati 1+3+5+7+9+11 aratati ca N =1+3+5+7+..................+999 este patratul unui nr

Answer 1

1+(1+2)+(2+3)+(3+4)+(4+5)+(5+6)=
(1+2+3+4+5)+(1+2+3+4+5+6)=
(5x6):2+(6x7):2=
30:2+42:2=
15+21
36


1+1+2+2+3+3+4+4+5+....499+500=
(1+2+3+....499)+(1+2+3+...500)=
(499x500):2+(500x501):2=
249500:2+(250500:2)=
124750+125250=
250 000

250 000 =2la4x5la6