3XY+10Y+[5X-(2XY+2Y-3X)]
=3XY+10Y+[5X-2XY-2Y+3X]
=3XY+10Y+（8X-2XY-2Y）
=3XY+10Y+8X-2XY-2Y
=3XY-2XY+10Y-2Y+8X
=XY+8Y+8X
=XY+8（Y+X）
∵XY=1,X+Y=3
∴原式=XY+8×（Y+X）=1＋8×3=25
XY=1,X+Y=3,则3XY+10Y+[5X-(2XY+2Y-3X)]
2个回答
相关问题
-
(5x²y-2xy²-3xy)-(2xy+5x²y-2xy²),x=-1/5,y
-
xy+ 2=0,x+y-3=0求(3xy+10y))+[5x-(2xy+2y-3x)]
-
5x²y-[2²y-(3xy-xy²)-3x²]-2xy²-y
-
若xy/x+y=2,则3x-xy+3y/-x+3xy-y=
-
若[1/x+1y]=2，则[2x−xy+2y/3x+5xy+3y]=______
-
若2/x+2/y=1,则（2x-xy+2y）/（3x+5xy+3y）=?
-
x+y=-5,xy=3,则-x^3y-xy^3+2x^2y^2等于
-
初一整式（3xy+10y）＋[5x-（2xy+2y-3x）],其中xy=-2,x+y=3.
-
已知x+y=5,xy=-1,则（3x-4y+2xy)-(2x-5y+5xy)=_______
-
已知x-y=3xy，则[2x+3xy−2y/x−2xy−y]=______．