中学生网络课堂
初二数学 (北师版)
二次根式
本课配套习题挑战模式1/5
单选题
难度系数：
1.若x-y=
，xy=
，则代数式（x-1）（y+1）的值等于（ ）
，xy=，则代数式（x-1）（y+1）的值等于（ ） A: 2 |
B: 2 |
| C: 2 |
D:  |
一次做对，真牛！
+5奖励规则>
- 提示1：IO+8iHgtMe+8ie+8iHkrMe+8iT14eSt4LXktMQ==
- 答案：Qg==
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
本课配套习题挑战模式2/5
单选题
难度系数：
2.若a=
，b=
，则
的值为（ ）
，b=，则的值为（ ） | A: 2 |
| B: -2 |
| C: |
| D: 2 |
一次做对，真牛！
+5奖励规则>
- 提示1：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
- 提示2：IDxpbWcgd2lkdGg9MjQgaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvNjcvMDAvckJBQ0ZGT1lKRU94czlTQkFBQUJsbFkwNkFBODQ5LnBuZyI+PTxpbWcgd2lkdGg9MTMyIGhlaWdodD0yMSBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwL0EzLzI0L3JCQUNFMU9ZSkVPekxrSGZBQUFDTlc1TGZpczcxNi5wbmciPj0x
- 提示3：IDxpbWcgd2lkdGg9NTEgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvQTMvMjQvckJBQ0UxT1lKRVBTMDJXM0FBQUNOVFpyNThjODg5LnBuZyI+PTxpbWcgd2lkdGg9NjEgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvQTMvMjQvckJBQ0UxT1lKRVBqZXlYLUFBQUNabmt0ZkZZNzIyLnBuZyI+
- 答案：QQ==
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
本课配套习题挑战模式3/5
单选题
难度系数：
3.已知x-2
，则
，则 A:  |
B:  |
C:  |
D:  |
一次做对，真牛！
+5奖励规则>
- 提示1：IOeUsXgtMjxpbWcgd2lkdGg9MTY3IGhlaWdodD00MiBzcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwL0EzLzI1L3JCQUNFMU9ZSkVpeW40UDdBQUFET2lKdmFqUTEwMC5wbmciPuWPr+W+l++8mjxpbWcgd2lkdGg9OTcgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvNjcvMDAvckJBQ0ZGT1lKRWlBVWdmdUFBQUN1QmhLaFZrNDE0LnBuZyI+77yM4oi0eD15
- 提示2：IOaKing9eeS7o+WFpTxpbWcgd2lkdGg9NjMgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvNjcvMDAvckJBQ0ZGT1lKRWpUb1lKdkFBQUMxR1lWd0xzOTA3LnBuZyI+
- 答案：RA==
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
本课配套习题挑战模式4/5
单选题
难度系数：
4.已知a＞b＞0，a+b=6
，则
的值为（ ）
，则的值为（ ）A:  |
| B: 2 |
| C: |
| D: |
一次做对，真牛！
+5奖励规则>
- 提示1：IOeUsWHvvJ5i77yeMO+8jGErYj02PGltZyB3aWR0aD0yNyBoZWlnaHQ9NDIgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC9BMy8yNS9yQkFDRTFPWUpFNnlTRkFNQUFBQnFIaHZJVm8yMzgucG5nIj7vvIzlj6/lvpc8aW1nIHdpZHRoPTEzOCBoZWlnaHQ9NDIgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC9BMy8yNS9yQkFDRTFPWUpFN0FIT3V3QUFBREdpY2p3cWszNTkucG5nIj4sPGltZyB3aWR0aD0xNDIgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvQTMvMjUvckJBQ0UxT1lKRTdoSEctS0FBQUROQmtoc2VNNTQxLnBuZyI+
- 提示2：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
- 答案：QQ==
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
本课配套习题挑战模式5/5
单选题
难度系数：
5.已知a=1-，b=+1，则代数式a2+ab+b2的值为（ ）
，b=+1，则代数式a2+ab+b2的值为（ ） | A: 3 |
| B: -3 |
| C: 5 |
| D: -5 |
一次做对，真牛！
+5奖励规则>
- 提示1：IOWPmOW9omE8c3VwPjI8L3N1cD4rYWIrYjxzdXA+Mjwvc3VwPj08aW1nIHdpZHRoPTgwIGhlaWdodD0yMSBzcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzY3LzAxL3JCQUNGRk9ZSkZQeTVJRXJBQUFCOVdHR0xKWTM4My5wbmciPg==
- 答案：Qw==
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
