四、巩固练习
- 把下列二元二次方程化为两个二元一次方程:
(1)x2-3xy+2y2=0(x-y=0,x-2y=0)
(2)2x2-5xy-3y2=0(2x+y=0,x-3y=0)
(3)x2-6xy+9y2=16(x-3y=4-3y=-4)
(4)x2-4xy+4y2-2x+4y-3=0
(x-3y=3,x-2y=-1) 2.解下列方程组:
x2 − 3xy + 2y2
= 0,
(1)3x 2
+ 2xy = 20;
x2 + y2 = 5,
(2)2x
2 − 3xy − 2y2
= 0.