计算:①(2x2y+2x+4)﹣2(x2y+2) ②(x﹣y+1)(x+y+1) ③(x﹣y)2(x2+y2)2(x+y)2④[(ab+3)(ab﹣3)﹣7a2
题型:解答题难度:一般来源:期中题
计算:①(2x2y+2x+4)﹣2(x2y+2) ②(x﹣y+1)(x+y+1) ③(x﹣y)2(x2+y2)2(x+y)2 ④[(ab+3)(ab﹣3)﹣7a2b2+9]÷(﹣2ab) |
答案
解:①(2x2y+2x+4)﹣2(x2y+2), =2x2y+2x+4﹣2x2y﹣4, =2x; ②(x﹣y+1)(x+y+1), =[(x+1)﹣y][(x+1)+y], =(x+1)2﹣y2, =x2+2x+1﹣y2; ③(x﹣y)2(x2+y2)2(x+y)2, =(x﹣y)2(x+y)2(x2+y2)2, =(x2﹣y2)2(x2+y2)2, =(x4﹣y4)2 =x8﹣2x4y4+y8; ④[(ab+3)(ab﹣3)﹣7a2b2+9]÷(﹣2ab), =(a2b2﹣9﹣7a2b2+9)÷(﹣2ab), =﹣6a2b2÷(﹣2ab), =3ab. |
举一反三
请你按下列程序进行计算,把答案填写在表格内,然后看看有什么规律,想想为什么会有这样的规律? |
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(1)填写表内的空格: |
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(2)你发现的规律是: _________ . (3)请说明你发现的规律 |
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