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(2013•南昌)先化简,再求值:x2-4x+42x÷x2-2xx2+1,在0,1,2三个数中选一个合适的,代入求值.

题目详情
(2013•南昌)先化简,再求值:
x2-4x+4
2x
÷
x2-2x
x2
+1,在0,1,2三个数中选一个合适的,代入求值.
▼优质解答
答案和解析
x2-4x+4
2x
÷
x2-2x
x2
+1
=
(x-2)2
2x
÷
x(x-2)
x2
+1
=
(x-2)2
2x
×
x2
x(x-2)
+1
=
x-2
2
+1
=
x
2

当x=0或2时,分式无意义,
故x只能等于1,
原式=
1
2