Carcass wrote:
If |ab| and |xy| are reciprocals and ab(xy)<0, which of the following must be true?
A. ab<0
B. ab(xy)<−1
C. ab<1
D. ab=−yx
E. yx>ab
We can either try to apply some number sense or simply test some values.
I have a feeling the latter might be faster.
If |a/b| and |x/y| are reciprocals, AND (a/b)(x/y) < 0, then it could be the case that: a = 1, b = 1, x = 1 and y = -1
Now check out the choices....
A.
(1)(1)<0 NOT TRUE
B.
11(1−1)<−1 NOT TRUE
C.
11<1 NOT TRUE
D.
11=−(−1)1 TRUE!
E.
−11>11 NOT TRUE
Answer: D
Cheers,
Brent