a+2a+..+100a+100b+99b+.+b
=(a+100a)x100÷2+(b+100b)x100÷2
=5050a+5050b
=5050(a+b)
=5050x0
=0是a+2a+100a+100b+99b+......+b你抄错题目了 这个没法算呃这是老师出抄在黑板上的题目她就是这么写的呀