(-2)+4+(-6)+8+(-10)+.(-98)+100=?

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/27 16:45:22
(-2)+4+(-6)+8+(-10)+.(-98)+100=?

(-2)+4+(-6)+8+(-10)+.(-98)+100=?
(-2)+4+(-6)+8+(-10)+.(-98)+100=?

(-2)+4+(-6)+8+(-10)+.(-98)+100=?
(-2) + 4 + (-6) + 8 +.+ (-98) + 100
= (-2 + 4) + (-6 + 8) + ...+ (-98 + 100)
= 2 + 2 + ...+ 2
= 2 × 25
= 50

(-2)+4=2
(-6)+8=2
100/4=25
25*2=50

一共有50个数,两两配对,相当于25对,如—2和4一对,—6和8一对,他们之和都是2,就相当于2*25=50

50

(-2) + 4 + (-6) + 8 +....+ (-98) + 100
= (-2 + 4) + (-6 + 8) + ... + (-98 + 100)
= 2 + 2 + ... + 2
= 2 × 25
= 50

(-2) + 4 + (-6) + 8 +....+ (-98) + 100
= (-2 + 4) + (-6 + 8) + ... + (-98 + 100)
= 2 + 2 + ... + 2
= 2 × 25
= 50