新SAT官方Daily Practice每日一题计算题(9.7)
- 2017年09月07日11:49 来源:小站教育作者:小站SAT编辑
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Read the following SAT test question and then click on a button to select your answer.
(x+10000)(x+10000)=0
How many unique real solutions does the equationabove have?
A.0
B.1
C.2
D.4
重点单词:
solution [sə'lu:ʃən]n. 解答,解决办法,溶解,溶液
multiple ['mʌltipl]adj. 许多,多种多样的n. 倍数,并联
unique [ju:'ni:k]adj. 独一无二的,独特的,稀罕的
equation [i'kweiʃən]n. 相等,方程(式), 等式,均衡
factor ['fæktə]n. 因素,因子
答案:B
解析:
Choice B is correct. The left-hand side of theequation can only be zero when one of the factors iszero.
If the first factor is zero, then x=-10000.
If the second factor is zero, then x=-10000.
These are both the same solution. So there is only 1 unique solution. This solution is alsoreal.
The equation has 1 unique real solution.