SAT数学Problem Solving练习题（22）

>>SAT考试：SAT数学Problem Solving练习题（22）

>>SAT考试辅导：精品课程高端指导

Question #22: If a·b + b·c + c·a = 0, what is (a + b)2 + (b + c)2 + (c + a)2?

(a) a2 + b2 + c2

(b) 2·(a2 + b2 + c2)

(c) (a2 + b2 + c2)/2

(d) a2 + a + b2 + b + c2 +c

(e) (a + b + c)/2

Answer: (a + b)2 + (b + c)2 + (c + a)2 = 2·(a2 + b2 + c2) + 2·(a·b + b·c + c·a)

Since a·b + b·c + c·a = 0, the correct result is 2·(a2 + b2 + c2).

想要了解更多习题？请继续关注坦途网SAT考试频道，让我们一起为考试冲刺！