问题
解答题
(1)请从三个代数式4x2-y2,2xy+y2,4x2+4xy+y2中,任选两个构造一个分式,并化简该分式;
(2)解方程:(x-1)2+2x-3=0.
答案
(1)本题答案不唯一.
(2分)4x2-y2 2xy+y2
=
(6分)(2x+y)(2x-y) y(2x+y)
=
(8分)2x-y y
②
=4x2-y2 4x2+4xy+y2
=(2x+y)(2x-y) (2x+y)2 2x-y 2x+y
=y(2x+y) (2x+y)(2x-y)
;y 2x-y
③
=2xy+y2 4x2-y2
=y(2x+y) (2x+y)(2x-y)
;y 2x-y
④
=2xy+y2 4x2+4xy+y2
=y(2x+y) (2x+y)2
;y 2x+y
⑤
=4x2+4xy+y2 4x2-y2
=(2x+y)2 (2x+y)(2x-y)
;2x+y 2x-y
⑥
=4x2+4xy+y2 2xy+y2
=(2x+y)2 y(2x+y)
.2x+y y
(2)x2-2x+1+2x-3=0(3分)
x2-2=0
x2=2(6分)
∴x1=
,x2=-2
.(8分)2