问题
填空题
若m2－n2=6，且m－n=2，则m＋n= ．
答案
3。
将m2－n2按平方差公式展开，再将m－n的值整体代入，即可求出m＋n的值：
∵
，
∴m＋n=3。
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若m2－n2=6，且m－n=2，则m＋n= ．
3。
将m2－n2按平方差公式展开，再将m－n的值整体代入，即可求出m＋n的值：
∵，
∴m＋n=3。
| 完形填空。 | ||||
| This is Mike’s classroom. There are 30 1 . There is a clock 2 the wall. 3 clock is very old. There are 4 students: eighteen boys and 5 girls. 6 is their teacher. She is a good teacher. It’s about 4 o’clock. It’s time to go home. Look 7 Mike! He 8 behind the 9 . And the door is 10 . | ||||
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