作业帮1.[(x+2y)²-(x-2y)²-(x+2y)(x-2y)-4y²]÷2x,其中x=-2,y=二分之一2.（x+3)(2x-5)-(2x+1)(x-8)=413.已知3的m次方×9的m次方×27的m次方×81的m次方=3的30次方,求m的值过程详细点 回答好就采纳
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![1.[(x+2y)²-(x-2y)²-(x+2y)(x-2y)-4y²]÷2x,其中x=-2,y=二分之一2.（x+3)(2x-5)-(2x+1)(x-8)=413.已知3的m次方×9的m次方×27的m次方×81的m次方=3的30次方,求m的值过程详细点 回答好就采纳](/uploads/image/z/976007-47-7.jpg?t=1.%5B%28x%2B2y%29%26%23178%3B-%28x-2y%29%26%23178%3B-%28x%2B2y%29%28x-2y%29-4y%26%23178%3B%5D%C3%B72x%2C%E5%85%B6%E4%B8%ADx%3D-2%2Cy%3D%E4%BA%8C%E5%88%86%E4%B9%8B%E4%B8%802.%EF%BC%88x%2B3%29%282x-5%29-%282x%2B1%29%28x-8%29%3D413.%E5%B7%B2%E7%9F%A53%E7%9A%84m%E6%AC%A1%E6%96%B9%C3%979%E7%9A%84m%E6%AC%A1%E6%96%B9%C3%9727%E7%9A%84m%E6%AC%A1%E6%96%B9%C3%9781%E7%9A%84m%E6%AC%A1%E6%96%B9%3D3%E7%9A%8430%E6%AC%A1%E6%96%B9%2C%E6%B1%82m%E7%9A%84%E5%80%BC%E8%BF%87%E7%A8%8B%E8%AF%A6%E7%BB%86%E7%82%B9++%E5%9B%9E%E7%AD%94%E5%A5%BD%E5%B0%B1%E9%87%87%E7%BA%B3)
1.[(x+2y)²-(x-2y)²-(x+2y)(x-2y)-4y²]÷2x,其中x=-2,y=二分之一2.（x+3)(2x-5)-(2x+1)(x-8)=413.已知3的m次方×9的m次方×27的m次方×81的m次方=3的30次方,求m的值过程详细点 回答好就采纳
1.[(x+2y)²-(x-2y)²-(x+2y)(x-2y)-4y²]÷2x,其中x=-2,y=二分之一
2.（x+3)(2x-5)-(2x+1)(x-8)=41
3.已知3的m次方×9的m次方×27的m次方×81的m次方=3的30次方,求m的值
过程详细点 回答好就采纳
1.[(x+2y)²-(x-2y)²-(x+2y)(x-2y)-4y²]÷2x,其中x=-2,y=二分之一2.（x+3)(2x-5)-(2x+1)(x-8)=413.已知3的m次方×9的m次方×27的m次方×81的m次方=3的30次方,求m的值过程详细点 回答好就采纳
1.原式={（x+2y+x-2y）[x+2y-（x-2y）]-[x²-(2y)²]-4y²}]÷2x
=(8xy-x²)÷2x=4y-x÷2=3
2.打开括号得：2x²-5x+6x-15-(2x²-16x+x-8)=41
16x=48
x=3
3.原式=3的m次方×3的2m次方×3的3m次方×3的4m次方=3的10m次方=3的30次方,由此可得m=3