①计算:22-(-12)-2+3-1-19+(π-3.14)0②化简:(a2-aa-1-aa+1)÷(1+1a2-1)③解方程:3x-2=2+x2-x.-数学

题目简介

①计算:22-(-12)-2+3-1-19+(π-3.14)0②化简:(a2-aa-1-aa+1)÷(1+1a2-1)③解方程:3x-2=2+x2-x.-数学

题目详情

①计算:22-(-
1
2
)-2+3-1-
1
9
+(π-3.14)0

②化简:(
a2-a
a-1
-
a
a+1
)÷(1+
1
a2-1
)

③解方程:
3
x-2
=2+
x
2-x
题型:解答题难度:中档来源:不详

答案

①原式=4-4+class="stub"1
3
-class="stub"1
3
+1
=1;-------------------------------(3分)

(
a2-a
a-1
-class="stub"a
a+1
)÷(1+class="stub"1
a2-1
)

=(a-class="stub"a
a+1
)×
(a+1)(a-1)
a2

=
a2+a-a
a+1
×
(a+1)(a-1)
a2

=a-1;

③最简公分母为x-2,
方程两边同乘以x-2,
得3=2(x-2)-x,
解得x=7.
检验:把x=7代入(x-2)=5≠0.
∴x=7是原方程的根---------------------(3分)

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