Question

若多项式x平方-2xy+y平方-x+y-1=0,求x-y的值

Answer 1

x²-2xy+y²-x+y-1=(x-y)²-(x-y)-1=0
设x-y=a则
a²-a-1=o
a=(1±√5)／2
即x-y==(1±√5)／2

Answer 2

x^2-2xy+y^2-x+y-1=0
(x-y)^2-(x-y)-1=0
令x-y=t
t^2-t-1=0
t1=(1+根号5) /2
t2=(1-根号5) /2

Answer 3

x平方-2xy+y平方-x+y-1=0
(x - y)^2 - (x - y) - 1 = 0
((x-y) - 1/2)^2 - 5/4 = 0
x-y - 1/2 = +- 5^(1/2) /2
x - y = (1 +- 5^(1/2))/2

Answer 4

原式化为（x-y）^2-(x-y)-1=0,就可以看作是一个关于x-y的方程了，自己应该可以解吧，在这边打不出根号，就不打了，望楼主采纳

Answer 5

（x-y)*2-(x-y)-1=0
x-y=(1+或-根5）/2

Answer 6

(1+根5)/2或者(1-根5)/2