问题
解答题
已知x2-4x+1=0,求代数式(
|
答案
原式=(
-x+3 x-2
)×1 x-2 3 (x+2)(x-2)
=
×x+2 x-2 3 (x+2)(x-2)
=3 (x-2)2
=
.3 x2-4x+4
∵x2-4x+1=0,
∴x2-4x=-1,
∴原式=
=1.3 -1+4
已知x2-4x+1=0,求代数式(
|
原式=(
-x+3 x-2
)×1 x-2 3 (x+2)(x-2)
=
×x+2 x-2 3 (x+2)(x-2)
=3 (x-2)2
=
.3 x2-4x+4
∵x2-4x+1=0,
∴x2-4x=-1,
∴原式=
=1.3 -1+4