计算.﹙2x+3y﹚﹙2x-3y﹚-﹙x+2y﹚﹙x-2y﹚.
问题描述:
计算.﹙2x+3y﹚﹙2x-3y﹚-﹙x+2y﹚﹙x-2y﹚.
[﹙2x+y﹚²-﹙2x+y﹚﹙2x-y﹚]÷2x-y.
答
﹙2x+3y﹚﹙2x-3y﹚-﹙x+2y﹚﹙x-2y﹚.
=4X²-9y²-x²+4y²
=3x²-5y²
[﹙2x+y﹚²-﹙2x+y﹚﹙2x-y﹚]÷(2x-y)
=(4x²+4xy+y²-4x²+y²)÷(2x-y)
=(4xy+2y²)/(2x-y)