1+3+5+7+9+…… +Is (2n-1) the square of N

1+3+5+7+9+…… +Is (2n-1) the square of N

1+3+5+7+9+…… +(2n-1)
=（1+2n-1)×n/2
=2n×n/2
=n²

The square of 2-1 = 3, the square of 3-2 = 5, the square of 7-6 = 13,
The square of 0 - the square of 1 + the square of 2 - the square of 3. - the square of 199 + the square of 200=

2²-1²=3=1+2,4²-3²=7=3+4,.,200²-199²=399=199+200
So 0 & # 178; - 1 & # 178; + 2 & # 178; - 3 & # 178; +. - 199 & # 178; + 200 & # 178;
=0+（2²-1²）+（4²-3²）+.+（200²-199²）
=0+1+2+3+4+.+199+200
=(1+200)×200÷2
=20100

Square of 1 = 1 + + square of 1 + 3 = 2 + + square of 1 + 3 + 5 = 3. To 1 + 3 + 5 + 7. + 119 =?

1 = 1 square (1 item) 1 + 3 = 2 square (2 items) 1 + 3 + 5 = 3 square (3 items) according to the law, it is equal to the square of the number of addend items 1 + 3 + 5 + + + 199, the total is (199 + 1) divided by 2, equal to 100 items, get 1 + 2 + 3 + + + + 199 = 100 square, I hope it can help you