Question

两个数的和是 $S$ 。给每个数都加上 $3$ ，再将所得的两个数分别翻倍。最后这两个数的和是多少？

The sum of two numbers is $S.$ Suppose $3$ is added to each number and then each of the resulting numbers is doubled. What is the sum of the final two numbers?

$2S + 3$

$3S + 2$

$3S + 6$

$2S + 6$

$2S + 12$

答案：E

知识点：代数变形分配律

难度评级：950

解答：

给每个数加 $3$ 后，总和从 $S$ 变为 $S + 6$ 。再把每个数翻倍，总和也翻倍，得到 $2(S + 6) = 2S + 12.$

因此，正确答案是 E。

Adding $3$ to each number raises the sum from $S$ to $S + 6.$ Doubling each number doubles the sum, giving $2(S + 6) = 2S + 12.$

Thus, the correct answer is E.

2001 AMC 12 第 1 题

答案：E

难度评级：950

解答：

其他年份的第 1 题