已知1/x+1/y=2,求(x+y+2xy+2y)÷(2xy+y)的值謝謝了,

已知1/x+1/y=2,求(x+y+2xy+2y)÷(2xy+y)的值謝謝了,


(x+y+2xy+2y)÷(2xy+y)=(x+y/2xy)+(2xy/2xy)+(2y/y)=x+y/2xy+3已知1/x+1/y=2∴x+y/2xy=1/2(1/X+1/y)=1/2×2=1則原式=1+3=4



已知-x+2y=5,則5(x-2y)^2 -8(x-2y)-5的值為()
A.80 B.-170 C.160 D.60


C.160
-x+2y=5
x-2y=-5
5(x-2y)^2 -8(x-2y)-5
=5*25-8*(-5)-5
=125+40-5
=165-5
=160



如果(m-3)x+2y的|m-2|此方+8=0是關於x,y的二元一次方程,試求m的值


(m-3)x+2y的|m-2|次方等於-8且是關於x,y的二元一次方程
|m-2|≠0(m-3)≠0,則m≠3,m≠2