Contact us
Choose a category below so we can get back to you as quickly as possible.
1995-1+2-3+4-5+…+1948-1949=1995-(1+1949+3+1947+…+975)+2+1948+4+1946+…+974+976=1995-975×975+975×974=1995-975×(975-974)=1995-975=1020;故答案為:1020.
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.