问题
计算题
因式分解:﹣4(x﹣2y)2+9(x+y)2.
答案
解:﹣4(x﹣2y)2+9(x+y)2
=[3(x+y)]2﹣[2(x﹣2y)]2
=(3x+3y+2x﹣4y)(3x+3y﹣2x+4y)
=(5x﹣y)(x+7y)
因式分解:﹣4(x﹣2y)2+9(x+y)2.
解:﹣4(x﹣2y)2+9(x+y)2
=[3(x+y)]2﹣[2(x﹣2y)]2
=(3x+3y+2x﹣4y)(3x+3y﹣2x+4y)
=(5x﹣y)(x+7y)