x=1-根号2,y=1+根号2,求(1⼀x+y+1⼀x-y)÷2x⼀X^2-2xy+y^2

2026年09月28日 03:07
有2个网友回答
网友(1):

∵x=1-√2,y=1+√2
∴x+y=2,x-y=-2√2
原式=2x/[(x+y)(x-y)]*(x-y)^2/(2x)
=(x-y)/(x+y)
=-2√2/2
=-√2

网友(2):

[1/(x+y)+1/(x-y)]÷[2x/(x²-2xy+y²)]
=[[(x-y)+(x+y)]/(x+y)(x-y)]/[2x/(x-y)²]
=[2x/(x+y)(x-y)]/[2x/(x-y)²]
=(2x)(x-y)²/[2x(x+y)(x-y)]
=(x-y)/(x+y)
=[(1-√2)-(1+√2)]/[(1-√2)+(1+√2)]
=-2√2/2
=-√2