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钟面上有1~12个数字,你能在某些数的前面添上符号,使添号后的12个数之和等于零吗?

来源:学生作业帮 编辑:拍题作业网作业帮 分类:数学作业 时间:2024/04/28 00:13:00
钟面上有1~12个数字,你能在某些数的前面添上符号,使添号后的12个数之和等于零吗?
你有几种添法?
124种:
1+2+3+4+5+6+7-8-9-10+11-12 = 0
1+2+3+4+5+6-7+8-9+10-11-12 = 0
1+2+3+4+5-6+7+8+9-10-11-12 = 0
1+2+3+4-5+6-7-8-9-10+11+12 = 0
1+2+3+4-5-6+7-8-9+10-11+12 = 0
1+2+3+4-5-6-7+8+9-10-11+12 = 0
1+2+3+4-5-6-7+8-9+10+11-12 = 0
1+2+3-4+5+6-7-8-9+10-11+12 = 0
1+2+3-4+5-6+7-8+9-10-11+12 = 0
1+2+3-4+5-6+7-8-9+10+11-12 = 0
1+2+3-4+5-6-7+8+9-10+11-12 = 0
1+2+3-4-5+6+7+8-9-10-11+12 = 0
1+2+3-4-5+6+7-8+9-10+11-12 = 0
1+2+3-4-5+6-7+8+9+10-11-12 = 0
1+2+3-4-5-6-7-8-9+10+11+12 = 0
1+2-3+4+5+6-7-8+9-10-11+12 = 0
1+2-3+4+5+6-7-8-9+10+11-12 = 0
1+2-3+4+5-6+7+8-9-10-11+12 = 0
1+2-3+4+5-6+7-8+9-10+11-12 = 0
1+2-3+4+5-6-7+8+9+10-11-12 = 0
1+2-3+4-5+6+7+8-9-10+11-12 = 0
1+2-3+4-5+6+7-8+9+10-11-12 = 0
1+2-3+4-5-6-7-8+9-10+11+12 = 0
1+2-3-4+5+6+7+8-9+10-11-12 = 0
1+2-3-4+5-6-7+8-9-10+11+12 = 0
1+2-3-4+5-6-7-8+9+10-11+12 = 0
1+2-3-4-5+6+7-8-9-10+11+12 = 0
1+2-3-4-5+6-7+8-9+10-11+12 = 0
1+2-3-4-5+6-7-8+9+10+11-12 = 0
1+2-3-4-5-6+7+8+9-10-11+12 = 0
1+2-3-4-5-6+7+8-9+10+11-12 = 0
1-2+3+4+5+6-7+8-9-10-11+12 = 0
1-2+3+4+5+6-7-8+9-10+11-12 = 0
1-2+3+4+5-6+7+8-9-10+11-12 = 0
1-2+3+4+5-6+7-8+9+10-11-12 = 0
1-2+3+4-5+6+7+8-9+10-11-12 = 0
1-2+3+4-5-6-7+8-9-10+11+12 = 0
1-2+3+4-5-6-7-8+9+10-11+12 = 0
1-2+3-4+5+6+7+8+9-10-11-12 = 0
1-2+3-4+5-6+7-8-9-10+11+12 = 0
1-2+3-4+5-6-7+8-9+10-11+12 = 0
1-2+3-4+5-6-7-8+9+10+11-12 = 0
1-2+3-4-5+6+7-8-9+10-11+12 = 0
1-2+3-4-5+6-7+8+9-10-11+12 = 0
1-2+3-4-5+6-7+8-9+10+11-12 = 0
1-2+3-4-5-6+7+8+9-10+11-12 = 0
1-2-3+4+5+6-7-8-9-10+11+12 = 0
1-2-3+4+5-6+7-8-9+10-11+12 = 0
1-2-3+4+5-6-7+8+9-10-11+12 = 0
1-2-3+4+5-6-7+8-9+10+11-12 = 0
1-2-3+4-5+6+7-8+9-10-11+12 = 0
1-2-3+4-5+6+7-8-9+10+11-12 = 0
1-2-3+4-5+6-7+8+9-10+11-12 = 0
1-2-3+4-5-6+7+8+9+10-11-12 = 0
1-2-3-4+5+6+7+8-9-10-11+12 = 0
1-2-3-4+5+6+7-8+9-10+11-12 = 0
1-2-3-4+5+6-7+8+9+10-11-12 = 0
1-2-3-4+5-6-7-8-9+10+11+12 = 0
1-2-3-4-5+6-7-8+9-10+11+12 = 0
1-2-3-4-5-6+7+8-9-10+11+12 = 0
1-2-3-4-5-6+7-8+9+10-11+12 = 0
1-2-3-4-5-6-7+8+9+10+11-12 = 0
-1+2+3+4+5+6+7-8-9-10-11+12 = 0
-1+2+3+4+5+6-7+8-9-10+11-12 = 0
-1+2+3+4+5+6-7-8+9+10-11-12 = 0
-1+2+3+4+5-6+7+8-9+10-11-12 = 0
-1+2+3+4-5+6+7+8+9-10-11-12 = 0
-1+2+3+4-5-6+7-8-9-10+11+12 = 0
-1+2+3+4-5-6-7+8-9+10-11+12 = 0
-1+2+3+4-5-6-7-8+9+10+11-12 = 0
-1+2+3-4+5+6-7-8-9-10+11+12 = 0
-1+2+3-4+5-6+7-8-9+10-11+12 = 0
-1+2+3-4+5-6-7+8+9-10-11+12 = 0
-1+2+3-4+5-6-7+8-9+10+11-12 = 0
-1+2+3-4-5+6+7-8+9-10-11+12 = 0
-1+2+3-4-5+6+7-8-9+10+11-12 = 0
-1+2+3-4-5+6-7+8+9-10+11-12 = 0
-1+2+3-4-5-6+7+8+9+10-11-12 = 0
-1+2-3+4+5+6-7-8-9+10-11+12 = 0
-1+2-3+4+5-6+7-8+9-10-11+12 = 0
-1+2-3+4+5-6+7-8-9+10+11-12 = 0
-1+2-3+4+5-6-7+8+9-10+11-12 = 0
-1+2-3+4-5+6+7+8-9-10-11+12 = 0
-1+2-3+4-5+6+7-8+9-10+11-12 = 0
-1+2-3+4-5+6-7+8+9+10-11-12 = 0
-1+2-3+4-5-6-7-8-9+10+11+12 = 0
-1+2-3-4+5+6+7+8-9-10+11-12 = 0
-1+2-3-4+5+6+7-8+9+10-11-12 = 0
-1+2-3-4+5-6-7-8+9-10+11+12 = 0
-1+2-3-4-5+6-7+8-9-10+11+12 = 0
-1+2-3-4-5+6-7-8+9+10-11+12 = 0
-1+2-3-4-5-6+7+8-9+10-11+12 = 0
-1+2-3-4-5-6+7-8+9+10+11-12 = 0
-1-2+3+4+5+6-7-8+9-10-11+12 = 0
-1-2+3+4+5+6-7-8-9+10+11-12 = 0
-1-2+3+4+5-6+7+8-9-10-11+12 = 0
-1-2+3+4+5-6+7-8+9-10+11-12 = 0
-1-2+3+4+5-6-7+8+9+10-11-12 = 0
-1-2+3+4-5+6+7+8-9-10+11-12 = 0
-1-2+3+4-5+6+7-8+9+10-11-12 = 0
-1-2+3+4-5-6-7-8+9-10+11+12 = 0
-1-2+3-4+5+6+7+8-9+10-11-12 = 0
-1-2+3-4+5-6-7+8-9-10+11+12 = 0
-1-2+3-4+5-6-7-8+9+10-11+12 = 0
-1-2+3-4-5+6+7-8-9-10+11+12 = 0
-1-2+3-4-5+6-7+8-9+10-11+12 = 0
-1-2+3-4-5+6-7-8+9+10+11-12 = 0
-1-2+3-4-5-6+7+8+9-10-11+12 = 0
-1-2+3-4-5-6+7+8-9+10+11-12 = 0
-1-2-3+4+5+6+7+8+9-10-11-12 = 0
-1-2-3+4+5-6+7-8-9-10+11+12 = 0
-1-2-3+4+5-6-7+8-9+10-11+12 = 0
-1-2-3+4+5-6-7-8+9+10+11-12 = 0
-1-2-3+4-5+6+7-8-9+10-11+12 = 0
-1-2-3+4-5+6-7+8+9-10-11+12 = 0
-1-2-3+4-5+6-7+8-9+10+11-12 = 0
-1-2-3+4-5-6+7+8+9-10+11-12 = 0
-1-2-3-4+5+6+7-8+9-10-11+12 = 0
-1-2-3-4+5+6+7-8-9+10+11-12 = 0
-1-2-3-4+5+6-7+8+9-10+11-12 = 0
-1-2-3-4+5-6+7+8+9+10-11-12 = 0
-1-2-3-4-5+6-7-8-9+10+11+12 = 0
-1-2-3-4-5-6+7-8+9-10+11+12 = 0
-1-2-3-4-5-6-7+8+9+10-11+12 = 0