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> (1)计算:2cos60°-2×(12)-1+|-3|+(2-1)0(2)有这样一道题:“计算:x2-2x+1x2-1÷x-1x2+x-x的值,其中x=2012.”甲同学把“x=2012”错抄成“x=
(1)计算:2cos60°-2×(12)-1+|-3|+(2-1)0(2)有这样一道题:“计算:x2-2x+1x2-1÷x-1x2+x-x的值,其中x=2012.”甲同学把“x=2012”错抄成“x=
题目简介
(1)计算:2cos60°-2×(12)-1+|-3|+(2-1)0(2)有这样一道题:“计算:x2-2x+1x2-1÷x-1x2+x-x的值,其中x=2012.”甲同学把“x=2012”错抄成“x=
题目详情
(1)计算:
2cos60°-2×(
1
2
)
-1
+|-3|+(
2
-1
)
0
(2)有这样一道题:“计算:
x
2
-2x+1
x
2
-1
÷
x-1
x
2
+x
-x
的值,其中x=2012.”甲同学把“x=2012”错抄成“x=2017”,但他计算结果也是正确的.请解释这是怎么回事.
题型:解答题
难度:中档
来源:桂平市三模
答案
(1)原式=2×
class="stub"1
2
-2×2+3+1=1;
(2)原式=
(x-1
)
2
(x+1)(x-1)
•
x(x+1)
x-1
-x=x-x=0,
∴原式的值与x的值无关,
则计算结果也是正确的.
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题目简介
(1)计算:2cos60°-2×(12)-1+|-3|+(2-1)0(2)有这样一道题:“计算:x2-2x+1x2-1÷x-1x2+x-x的值,其中x=2012.”甲同学把“x=2012”错抄成“x=
题目详情
(2)有这样一道题:“计算:
答案
(2)原式=
∴原式的值与x的值无关,
则计算结果也是正确的.