Question

100+99+98+97+96...... 4+3+2+1

简便运算，急！！！！
今天答案一定要出来

Answer 1

100+99+98+97+96...... 4+3+2+1=(100+99+98+97+96...... 4+3+2+1+1+2+3+4...... +96+97+98+99+100)/2=(101*100)/2=5050

高斯的倒序相加法！

Answer 2

99*100+100=10000

Answer 3

100+(99+1)+(98+2)+…(51+49)+50=50*100+50=5050

Answer 4

(100+1）*100/2;
公式：（首项+末项）*项数/2；
项数=（末项-首项）/公差+1 或（首项-末项）/公差+1

Answer 5

=(100+1)*50
=101*50
=5050

Answer 6

(100+1)*100/2
=101*100/2
=10100/2
=5050
(99+1)*50+50
=100*50+50
=5000+50
=5050