大师作文网已知x+y=4,xy=3,求：（1）x^2y-xy^2;（2）(x^2+1)(y^2+1)
来源：学生作业帮 编辑：大师作文网作业帮 分类：数学作业 时间：2024/11/17 10:07:16
已知x+y=4,xy=3,求：（1）x^2y-xy^2;（2）(x^2+1)(y^2+1)
x+y=4,xy=3
(x-y)^2=(x+y)^2-4xy
(x-y)^2=4^2-4*3
(x-y)^2=16-12
(x-y)^2=4
x-y=±2
x^2y-xy^2
=xy(x-y)
=±2*3
=±6
(x^2+1)(y^2+1)
=x^2(y^2+1)+(y^2+1)
=x^2y^2+x^2+y^2+1
=x^2y^2+x^2+y^2+2xy-2xy+1
=x^2y^2-2xy+1+x^2+y^2+2xy
=(xy-1)^2+(x+y)^2
=(3-1)^2+4^2
=2^2+16
=4+16
=20
(x-y)^2=(x+y)^2-4xy
(x-y)^2=4^2-4*3
(x-y)^2=16-12
(x-y)^2=4
x-y=±2
x^2y-xy^2
=xy(x-y)
=±2*3
=±6
(x^2+1)(y^2+1)
=x^2(y^2+1)+(y^2+1)
=x^2y^2+x^2+y^2+1
=x^2y^2+x^2+y^2+2xy-2xy+1
=x^2y^2-2xy+1+x^2+y^2+2xy
=(xy-1)^2+(x+y)^2
=(3-1)^2+4^2
=2^2+16
=4+16
=20
已知：x-y=1,xy=-2.求：(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)
已知x-y=3,xy=1,求（-2x+2x+3y)-(3xy+2y-2x)-(x+4y+xy)
1.已知x+y=-4,xy=3,求5（2分之1xy+2y）+[6x-(2xy+y-3x)]的值
已知（x+2）*+|y+1|=0求5xy*-｛2x*y-【3xy*-（4xy*-2x*y）】｝的值
已知1/x-1/y=3,求(3x+4xy-3y)/(x-2xy-y)的值
已知1/x+1/y=3,求3x-4xy+3y/(x+2xy+y)的值
已知:xy+x=-1,xy-y=-2,求多项式-x-[2y-2(xy+x)的平方+3x]+2[x+(xy-y)的平方]的
1/x-1/y=4,求分式（3x+xy-3y）/(x-2xy-y)
已知x+y=-1,xy=-2,求代数式-5（x+y)+(x-y)+x(xy+y)的值
1、已知x+y=-2,xy=3,求代数式2（x+xy）-[（xy-3y）-x]-（-xy）