(1)1+2-3-4+5+6-7-8+9+10-11-12+13+14-15-16=?这道题求过程(2)已知ab互为相反数,xy互为倒数,

2024-12-01 05:37:28
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回答1:

(1)1+2-3-4+5+6-7-8+9+10-11-12+13+14-15-16
= 1-3+2-4+5-7+6-8+9-11+10-12+13-15+14-16
=(1-3)+(2-4)+(5-7)+(6-8)+(9-11)+(10-12)+(13-15)+(14-16)
=-2-2-2-2-2-2-2-2
= -16

(2)
ab互为相反数,xy互为倒数,所以a+b=0 ,xy=1
2a+2b-20xy+10m=2(a+b)-20+10m=10m-20

当m=2时 解得 0 当m=-2 时,解得-40

(3)20.13*83.2+201.3*1.93-2013/40

=20.13*83.2+20.13*19.3-20.13*100/40
=20.13*(83.2+19.3-100/40)
=20.13*100
=2013

(4)1000+500+10000*8%+(25600-10000)*10%

=1500+800+1560
=3860