( 100^ 2 +90^ 2 +80^ 2 + cdots cdots cdots cdots cdots cdots cdots cdots+n^ 2 )

100^{2}+90^{2}+80^{2}+\cdots \cdots \cdots \cdots \cdots \cdots \cdots \cdots+n^{2}

SB 25

100^{2}+90^{2}+80^{2}+\cdots \cdots \cdots \cdots \cdots \cdots \cdots \cdots+n^{2}

SB 25