若1/x+1/y=2,则(2x-xy+2y)÷(3x+5xy+3y)
问题描述:
若1/x+1/y=2,则(2x-xy+2y)÷(3x+5xy+3y)
答
(2x-xy+2y)÷(3x+5xy+3y)
=(2/y-1+2/x)/3/y+5+3/x)
=3/11
答
1/x+1/y=2
y+x=2xy
(2x-xy+2y)=2(x+y)-xy=3xy
(3x+5xy+3y)=3(x+y)+5xy=11xy
(2x-xy+2y)÷(3x+5xy+3y)=3xy/11xy=3/11