问题
解答题
(1)化简:(
(2)解方程组
|
答案
(1)原式=(
+
•b b
(b
+a
)b
)•
• a a
(a
-b
)a
•
+a b ab
,a-b
+a b
=(
+b
+a b
)•a
-b a
,a-b ab
=
•b-
+a+ab ab b-a
,a-b ab
=
;-a-b ab
(2)
,x2-3xy+2y2+4x+3y-1=0 ① 2x2-6xy+y2+8x+2y-3=0 ②
①×2得:2x2-6xy+4y2+8x+6y-2=0,③
③-②得;3y2+4y+1=0,
解得:y1=-1,y2=-
,1 3
把y1=-1代入①得:x2+7x-2=0,
解得:x1=
,x2=7+ 57 2
,7- 57 2
把y2=-
代入①得:x2+5x-1 3
=0,16 9
解得:x1=-
,x2=16 3
,1 3
∴方程组的解为
,x1= 1 3 y1=- 1 3
,x2=- 16 3 y2=- 1 3
,x3= -7+ 57 2 y3=-1
.x4= -7- 57 2 y4=-1