(1)计算:327+(x-2)0-(15)-1-2cos45°(2)先化简,再求值:(m2-1m2-2m+1+mm2-m)÷(1+2m),其中m=-3.-数学

题目简介

(1)计算:327+(x-2)0-(15)-1-2cos45°(2)先化简,再求值:(m2-1m2-2m+1+mm2-m)÷(1+2m),其中m=-3.-数学

题目详情

(1)计算:
327
+(x-2)0-(
1
5
)
-1
-2cos45°
(2)先化简,再求值:(
m2-1
m2-2m+1
+
m
m2-m
)÷(1+
2
m
),其中m=-3.
题型:解答题难度:中档来源:本溪

答案

(1)原式=3+1-5-
2

=-
2
-1;

(2)原式=[
(m+1)(m-1)
(m-1)2
+class="stub"m
m(m-1)
class="stub"m+2
m

=(class="stub"m+1
m-1
+class="stub"1
m-1
)÷class="stub"m+2
m

=class="stub"m+2
m-1
class="stub"m
m+2

=class="stub"m
m-1

当m=-3时,原式=class="stub"-3
-3-1
=class="stub"3
4

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