1.已知1/x-1/y=3 求代数式2x-14xy-2y/x-2xy-y的值

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/11/06 00:48:57

1.已知1/x-1/y=3 求代数式2x-14xy-2y/x-2xy-y的值
2.分解因式(x+2)(x+4)+x²-4

1.已知1/x-1/y=3
2x-14xy-2y/x-2xy-y
=[2(x-2xy-y)-10xy]/(x-2xy-y)
=2- 10xy/(x-2xy-y)
=2+10xy/5xy
=2+2=4
2.分解因式(x+2)(x+4)+x²-4
=（x+2)(x+4)+(x-2)(x+2)
=(x+2)(x+4+x-2)
=(x+2)(2x+2)
=2(x+2)(x+1)

已知x+y=-1,xy=-2,求代数式-5（x+y)+(x-y)+x(xy+y)的值已知x+y=-1,xy=-2,求代数式-5（x+y)+(x-y)+2(xy+y)的值已知X+Y=-1,xy=-2,求代数式-5(x+y)+(x-y)+(xy+y)的值已知xy/x+y=2,求代数式3x-5xy+3y/-x+2xy-y的值已知xy/x+y=2,求代数式3x-xy+3y/-x+3xy-y的值已知x-y=2xy,求代数式3x-5xy-3y/x+xy-y的值 1.已知1/x-1/y=3 求代数式2x-14xy-2y/x-2xy-y的值已知y=3+xy,求代数式2x+3xy-2y/x-2xy-y的值. 已知x-y=1 求代数式x^4-xy^3-x^3y-3x^2y+3xy^2+y^4的值已知x+y=1，xy=-2，试求代数式（xy+5x-2y）-（-3xy+2x-5y）的值．已知x+y=1,xy=-2,试求代数式（xy+5x-2y）-（-3xy+2x-5y）的值已知x+2y=2,xy=1,求代数式2x+4y+3xy+1的值