问题
解答题
(1)计算:|
(2)先化简,再求值:(
|
答案
(1)|
-2|+20100-(-3
)-1+3tan30°,1 3
=2-
+1-(-3)+3×3
,3 3
=2-
+1+3+3
,3
=6;
(2)(
-4)÷x2+4 x
,x2-4 x2+2x
=
•(x-2)2 x
,x(x+2) (x+2)(x-2)
=x-2;
当x=-1时,原式=x-2=-1-2=-3.
(1)计算:|
(2)先化简,再求值:(
|
(1)|
-2|+20100-(-3
)-1+3tan30°,1 3
=2-
+1-(-3)+3×3
,3 3
=2-
+1+3+3
,3
=6;
(2)(
-4)÷x2+4 x
,x2-4 x2+2x
=
•(x-2)2 x
,x(x+2) (x+2)(x-2)
=x-2;
当x=-1时,原式=x-2=-1-2=-3.