2道计算题
计算：（3/4x²y-3/5x²y²)(-xy)²-(-2x²y²-3)(-3+2x²y²...
计算：（3/4x²y-3/5x²y²)(-xy)²-(-2x²y²-3)(-3+2x²y²﹚
计算：（2x+3﹚²﹙﹣2x+3﹚²-﹙x+1﹚²﹙x-1﹚² 展开
计算：（2x+3﹚²﹙﹣2x+3﹚²-﹙x+1﹚²﹙x-1﹚² 展开
1个回答
展开全部
（3/4x²y-3/5x²y²)(-xy)²-(-2x²y²-3)(-3+2x²y²﹚
=（3/4x²y-3/5x²y²)x²y²+(2x²y²+3)(2x²y²-3﹚
=3/4x^4y³-3/5x^4y^4+4x^4y^4-9
=3/4x^4y³+17/5x^4y^4-9
（2x+3﹚²﹙﹣2x+3﹚²-﹙x+1﹚²﹙x-1﹚²
=[（3+2x﹚﹙3﹣2x﹚]²-[﹙x+1﹚﹙x-1﹚]²
=(9-4x²)²-(x²-1)²-(x²-1)²
=(81-72x²+16x^4)-(x^4-2x²+1)
=81-72x²+16x^4-x^4+2x²-1
=15x^4-70x²+80
=（3/4x²y-3/5x²y²)x²y²+(2x²y²+3)(2x²y²-3﹚
=3/4x^4y³-3/5x^4y^4+4x^4y^4-9
=3/4x^4y³+17/5x^4y^4-9
（2x+3﹚²﹙﹣2x+3﹚²-﹙x+1﹚²﹙x-1﹚²
=[（3+2x﹚﹙3﹣2x﹚]²-[﹙x+1﹚﹙x-1﹚]²
=(9-4x²)²-(x²-1)²-(x²-1)²
=(81-72x²+16x^4)-(x^4-2x²+1)
=81-72x²+16x^4-x^4+2x²-1
=15x^4-70x²+80
来自：求助得到的回答
本回答由提问者推荐
已赞过
已踩过<
评论
收起
你对这个回答的评价是？
推荐律师服务：
若未解决您的问题，请您详细描述您的问题，通过百度律临进行免费专业咨询
