Question

求下式的值： $\begin{aligned} &1 - (-2) - 3 - (-4) \\ &\quad {}- 5 - (-6)? \end{aligned}$

What is the value of $\begin{aligned} &1 - (-2) - 3 - (-4) \\ &\quad {}- 5 - (-6)? \end{aligned}$

$-20$

$-3$

$3$

$5$

$21$

答案：D

知识点：整数运算

难度评级：450

解答：

减去负数等于加上对应的正数，所以合并各项可得 $\begin{aligned} &1-(-2)-3-(-4) \\ &\quad {}-5-(-6) \\ &\quad = 1+2-3+4-5+6. \end{aligned}$ $\begin{aligned} &(1+2+4+6)-(3+5) \\ &\quad = 13-8=5. \end{aligned}$

所以正确答案是 D。

Subtracting a negative is the same as adding the corresponding positive number, so $\begin{aligned} &1-(-2)-3-(-4) \\ &\quad {}-5-(-6) \\ &\quad = 1+2-3+4-5+6. \end{aligned}$ Now combine the terms: $\begin{aligned} &(1+2+4+6)-(3+5) \\ &\quad = 13-8=5. \end{aligned}$

Thus, D is the correct answer.

2020 AMC 10B 第 1 题

答案：D

难度评级：450

解答：

其他年份的第 1 题