Question

1＋3＝＿的平方,1＋3＋5＝＿的平方,1＋3＋5＋7＝＿的平方

Answer 1

1+3=[(1+3)/2]^2=2^2

1+3+5=[(1+5)/2]^2=3^2

1+3+5+7=[(1+7)/2]^2=4^2

.

1＋3＋5＋7……＋2005＝[(1+2005)/2]^2=1003^2

1+3+...+2n-1=n^2