位置:首页 > SAT > SAT每日一题 > 正文
SAT官方每日一题附答案和解析[数学](2015年2月15日)
日期:2015-02-15 14:55

(单词翻译:单击)

每日一题

Mathematics>Standard Multiple Choice


Read the following SAT test question and then click on a button to select your answer.

First, 3 is subtracted from x and the square root of the difference is taken. Then, 5 is added to the result, giving a final result of 9. What is the value of x?

(A) 3
(B) 4
(C) 5
(D) 16
(E) 19

答案和解析

答案:E

解析:

When 3 is subtracted from x, the result is x-3. The square root of this difference is square root (x-3). When 5 is added to square root (x-3), the final result is 9. This can be written as (square root (x-3)) plus 5 = 9. Subtracting 5 from both sides gives the equation square root (x-3) = 4. Squaring both sides of this equation gives x-3 = 16, or x = 19.

分享到
重点单词
  • multipleadj. 许多,多种多样的 n. 倍数,并联
  • equationn. 相等,方程(式), 等式,均衡