SAT数学Problem Solving练习题（28）
- 2017年07月26日13:38 来源：互联网
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摘要：下面是小站SAT频道为大家整理了SAT数学Problem Solving练习题(28)，供考生们参考，以下是详细内容。
以下是小站SAT频道为大家整理了SAT数学Problem Solving练习题(28)，供考生们参考，以下是详细内容。
Question 28: What are the solutions of the equation 5x(x + 1)·5x = 1?
(a) x1 = 0 and x2 = 2
(b) x1 = 0 and x2 = 1
(c) x1 = 2 and x2 = -2
(d) x1 = 0 and x2 = -2
(e) x1 = 1 and x2 = -2
Answer: The left side of the equation: 5x·(x + 1)·5x = 5x2 + 2x.
The right side of the equation: 1 = 50.
5x2 + 2x = 50
x2 + 2x = 0, x·(x + 2) = 0, and x1 = 0 and x2 = -2
