化简求值:2xy^2-[3xy^2-2(x^2y-(1/2)xy^2)]-2x^2y其中x=-2/3,y=-1/2
来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/10/03 14:31:54
化简求值:2xy^2-[3xy^2-2(x^2y-(1/2)xy^2)]-2x^2y其中x=-2/3,y=-1/2
2xy^2-[3xy^2-2(x^2y-(1/2)xy^2)]-2x^2y
=2xy²-[4xy²-2x²y]-2x²y
=2xy²﹣4xy²﹢2x²y﹣2x²y
=﹣2xy²
=﹣2×﹙﹣2/3﹚﹙﹣1/2﹚
=﹣2/3
再问: ﹣2×﹙﹣2/3﹚﹙﹣1/2﹚ (﹣1/2﹚不是平方吗
再答: 漏了 2xy^2-[3xy^2-2(x^2y-(1/2)xy^2)]-2x^2y =2xy²-[4xy²-2x²y]-2x²y =2xy²﹣4xy²﹢2x²y﹣2x²y =﹣2xy² =﹣2×﹙﹣2/3﹚﹙﹣1/2﹚² =1/3
=2xy²-[4xy²-2x²y]-2x²y
=2xy²﹣4xy²﹢2x²y﹣2x²y
=﹣2xy²
=﹣2×﹙﹣2/3﹚﹙﹣1/2﹚
=﹣2/3
再问: ﹣2×﹙﹣2/3﹚﹙﹣1/2﹚ (﹣1/2﹚不是平方吗
再答: 漏了 2xy^2-[3xy^2-2(x^2y-(1/2)xy^2)]-2x^2y =2xy²-[4xy²-2x²y]-2x²y =2xy²﹣4xy²﹢2x²y﹣2x²y =﹣2xy² =﹣2×﹙﹣2/3﹚﹙﹣1/2﹚² =1/3
化简求值3x²y-[2xy-2(xy-3/2x²y)+xy]+3xy²其中x=3、y=-1
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,
(x+2y-3xy)-(-2x-y+xy),其中x+y=,xy=-,求值.
化简求值:(-1/3XY)²[xy(2x-y)-2x(xy-y²)],其中X=-3/2,Y=-2
先化简再求值:xy^3÷(-xy)+(x+2y)(x-2y),其中x=根号2,y=1
5xy平方-2x平方y+[3xy平方-(4xy-2x平方y-2x平方y)],其中x=-2,y=-1求值
①化简求值:2(x^2y+xy)-3(x^2y-xy)-4x^2y,其中x=1,y=-1.
化简求值:2(x的平方y+xy)-3(x平方y+xy)-4x平方y,其中x=-1,y=2
先化简再求值:2(xy^2-2y+1/2xy)-(xy+3xy^2-4y),其中x=4,y=1/2,
化简求值{(-1/2x^3y^4)^3+(-1/6xy^2)^2*3xy^2}/(-1/2xy^2)^3其中X=-2,y
化简求值(1)2x^2y(-2xy^2)^3+(2xy)^3(-xy^2)^2,其中x=3,y=1/4