SOLUTION: If n < 0, which of the following could be true? I. 2n < n^2 II. 2n < n III. n^2 < – n (A) None (B) I only (C) I and II only (D) I and III only (E) I, I

Algebra ->  Inequalities -> SOLUTION: If n < 0, which of the following could be true? I. 2n < n^2 II. 2n < n III. n^2 < – n (A) None (B) I only (C) I and II only (D) I and III only (E) I, I      Log On


   



Question 315142: If n < 0, which of the following could be true?
I. 2n < n^2
II. 2n < n
III. n^2 < – n
(A) None (B) I only (C) I and II only
(D) I and III only (E) I, II, and III

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
E) is the correct answer.
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I. when n%3C0, n%5E2%3En always.
n%5E2%3En
Divide by n and change the sign of the inequality
highlight%28n%3C1%29
.
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II. when n%3C0, 2n%3Cn always.
2n%3Cn
Divide by n and change the sign of the inequality
highlight%282%3E1%29
.
.
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III. when n%3C0, n%5E2%3C-n holds when -1%3Cn%3C0
n%5E2%3C-n
Divide by n and change the sign of the inequality
highlight%28n%3E-1%29