问题
解答题
先化简,再求值:(
|
答案
原式=(
-2)•(x-1)x2-3 x-1
=
•(x-1)-2(x-1)x2-3 x-1
=x2-3-2x+2
=x2-2x-1
由x2-2x-3=0,得x2-2x=3
∴原式=3-1=2.
先化简,再求值:(
|
原式=(
-2)•(x-1)x2-3 x-1
=
•(x-1)-2(x-1)x2-3 x-1
=x2-3-2x+2
=x2-2x-1
由x2-2x-3=0,得x2-2x=3
∴原式=3-1=2.