问题
解答题
(1)计算:(
(2)先化简,再求值 (1-
|
答案
(1)原式=1+
-1-(2
+1)×1-(-1),2
=1+
-1-2
-1+1,2
=0.
(2)原式=[
-x+3 x+3
]×x-3 x+3
,(x+3)(x-3) 2x
=
×6 x+3
,(x+3)(x-3) 2x
=
,3(x-3) x
当x=4时,
原式=
,3×(4-3) 4
=
.3 4
(1)计算:(
(2)先化简,再求值 (1-
|
(1)原式=1+
-1-(2
+1)×1-(-1),2
=1+
-1-2
-1+1,2
=0.
(2)原式=[
-x+3 x+3
]×x-3 x+3
,(x+3)(x-3) 2x
=
×6 x+3
,(x+3)(x-3) 2x
=
,3(x-3) x
当x=4时,
原式=
,3×(4-3) 4
=
.3 4