如果XY\/X+Y=2,求代数式3X-5Y+3Y\/-X+3XY-Y的值为 ?没错!
"代数式3X-5Y+3Y\/-X+3XY-Y的值为 "确定题目没错 分子的"-5Y"和"+3Y"是同类项 若是"代数式3X-5XY+3Y\/-X+3XY-Y的值为 "则答案是 3X-5XY+3Y\/-X+3XY-Y =（3X-5XY+3Y）\/（-X+3XY-Y）=[3(X+Y)\/(XY)-5]\/[3-（X+Y)\/(XY）]=(3\/2-5)\/(3-1\/2)=-7\/5 =-1.4 ...
已知xy x+y =2 ,求代数式 3x-5xy+3y -x+3xy-y 的值
∵ xy x+y =2∴xy=2（x+y）∴原式= 3x-5×2(x+y)+3y -x+3×2(x+y)-y = -7x-7y 5x+5y = - 7 5
已知xy\/x+y=2,求代数式3x—5xy+3y\/—x+3xy—y的值
解：∵xy\/（x+y）=2 ∴xy=2（x+y）将xy=2（x+y）代入代数式内，得：3x—5xy+3y\/—x+3xy—y=3x—5×2（x+y）+3y\/-x+3×2（x+y）-y=-7（x+y）\/5（x+y）=-7\/5
若X+Y=3,XY=1,则-5X-5Y+3XY的值是多扫?
-5X-5Y+3XY =-5(x+y)+3xy ∵X+Y=3，XY=1 ∴原式=-15+3 =-12
已知xy\/x+y=2,求代数式3x-5y+3y\/-x+3xy-y的值
因为xy\/（x+y）=2 →(x+y)=xy\/2 则（3x-5y+3y）\/（-x+3xy-y）=[3(x+y)-5y]\/[-(x+y)+3xy]=[3*(xy\/2)-5y]\/[-xy\/2 +3xy]=(3xy\/2 -5y)\/(5xy\/2)=3\/5-2\/x
已知多项式x+y分之xy=2,求代数式-x+3xy-y分之3x-5xy+3y的值
x+y分之xy=2，则 xy\/(x+y)=2 xy=2x+2y (-x+3xy-y)分之(3x-5xy+3y)=(3x-5xy+3y)\/(-x+3xy-y)=[3x-5(2x+2y)+3y)\/[-x+3(2x+2y)-y]=(3x-10x-10y+3y)\/(-x+6x+6y-y)=(-7x-7y)\/(5x+5y)=[-7(x+y)]\/[5(x+y)]=-7\/5 =-1.4 ...
已知xy除以x+y=2,求代数式3x-5xy+3y除以﹣x+3xy-y的值
xy\/（x+y）=2 , xy=2（x+y）(x-5xy+3y)\/(﹣x+3xy-y)=(x-5*2（x+y）+3y)\/(﹣x+3*2（x+y）-y)=(3x-10x-10y+3y)\/(-x-6x-6y-y)=(-7x-7y)\/(-7x-7y)=1
以知XY除以X+Y等于2 求代数式3X--5XY+3Y除以(--X+3XY--Y) 提示把XY...
（3X--5XY+3Y）\/(--X+3XY--Y)=【3（X+Y）-5XY】\/【3XY-（X+Y）]上下同时除以（X+Y)得出：【3-5XY\/（X+Y)】\/3XY\/（X+Y)-1 =（3-10）\/（6-1）=-7\/5 XY\/（X+Y)=2
已知x加y分之xy等于2,求负x加3xy减y分之3x减5xy加3y
已知 xy\/(x+y) = 2，求:(3x-5xy+3y)\/(-x+3xy-y)xy\/(x+y) = 2得：xy=2(x+y)(3x-5xy+3y)\/(-x+3xy-y)=(3x-9xy+3y+4xy)\/(-x+3xy-y)= -3 + 4xy\/(-x+3xy-y)= -3 + 8(x+y)\/(-x+6x+6y-y)= -3 + 8(x+y)\/5(x+y)= -3 + 8\/5 = -7\/5 祝...
已知x+y=3,xy=-2,求(3x-4y+2xy)-(2x-5y+5xy)的值
（3x-4y+2xy）-（2x-5y+5xy）=3x-4y+2xy-2x+5y-5xy =x+y-3xy =3-3x（-2）=3+6 =9 祝学习进步，望采纳，不懂的欢迎追问...
