Question

求教教，这题怎么解

Answer 1

望采纳，氏斗尘谢歼禅销物谢啦

Answer 2

2*x*x-x*y-y*y=0

2.25*x*x=(0.5*x+y)*(0.5*x+y)...............(1)

x*x-y*y+2y-1=0
x*x=(y-1)*(y-1)..........................(2)

1.5*(y-1)=±(0.5*x+y)
x=y-3，或，x=5y+3，分别代入(2)，解得：薯灶岁
x=y-3时，y=2，x=-1
或数睁，
x=5y+3时，
y=2/3，x=19/3
或，辩数y=0.5，x=11/2

Answer 3

2x²-xy-y²=0 (1)
x²-y²+2y-1=0 (2)

由(2)式得：
x²-(y²-2y+1)=0
x²=(y-1)²
x=±(y-1)

代入(1)式得昌雀稿:
2(y-1)²±(y-1)y-y²=0
2y²岁枯-4y+2±(y-1)y-y²=0

(a) x=+(y-1) :
2y²-4y+2+y²-y-y²=0
2y²-5y+2=0
(2y-1)(y-2)=0
y=0.5 x=-0.5
y=2 x=1

(b) x=-(y-1) :
2y²-4y+2-y²耐孝+y-y²=0

-3y+2=0
y=2/3
x=-2/3+1=1/3