1^2-2^2+3^2-4^2+5^2-…-98^2+99^2-100^2+101^2
=(1-2)*(1+2) + (3-4)*(3+4) + ... +(99-100)*(99+100) + 101^2
= - (1+2+...+100) + 101^2
= 5151
1^2-2^2+3^2-4^2+5^2-…-98^2+99^2-100^2+101^2
=(1-2)*(1+2) + (3-4)*(3+4) + ... +(99-100)*(99+100) + 101^2
= - (1+2+...+100) + 101^2
= 5151