(1)计算:-22+(12-1)0+2sin30°(2)先化简,再求值:x2-1x2-2x+1+x2-2xx-2÷x,其中x=2.-数学

题目简介

(1)计算:-22+(12-1)0+2sin30°(2)先化简,再求值:x2-1x2-2x+1+x2-2xx-2÷x,其中x=2.-数学

题目详情

(1)计算:-22+(
1
2
-1
0+2sin30°
(2)先化简,再求值:
x2-1
x2-2x+1
+
x2-2x
x-2
÷x,其中x=2
题型:解答题难度:中档来源:不详

答案

(1)-22+(class="stub"1
2
-1
)0+2sin30°
=-4+1+2×class="stub"1
2

=-4+1+1
=-2;
(2)
x2-1
x2-2x+1
+
x2-2x
x-2
÷x
=class="stub"x+1
x-1
+1
=class="stub"2x
x-1

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