x^2+y^2=5,xy=2
则(x+y)²=x²+y²+2xy=5+4=9
则x+y=3或-3
1/x+1/y
=y/(xy)+x/(xy)
=(x+y)/(xy)
=3/2或-3/2
若x^2+y^2=5,xy=2,则1/x+1/y=?
1个回答
相关问题
-
若x/1-y/1=5,则x-2xy-y/2x+5xy-2y=?
-
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）=?
-
若1/X-1/Y=3,则2X+XY-2Y/X-2XY-Y=?
-
若(2x-14xy-2y)除以(x-2xy-y)=4,则1/x-1/y=
-
若x-y=2，则[1/2]（x2+y2）-xy=______．
-
若x²-2x+√(y-1/2)=-1,则x²+4xy+2y²=?
-
若[1/x]+[1/y]=2，则[2x+3xy+2y/x−xy+y]的值为______．
-
若x^2+y^2=8.25,x-y=1.5,则(xy)^4=
-
若x2+y2=3,xy=1,则x-y=?