(A) -x < -4
(B) -x > 4
(C) -x < 4
(D) -x > -4
If x > -4, then which of the following must be true?
2016-08-10 3:05 pm
回答 (5)
2016-08-10 3:38 pm
✔ 最佳答案
x > −4
x+4 > 0
4 > −x
−x < 4
or
Start with x > −4, Multiply both sides by −1
When multiplying or dividing both sides of inequality by negative number, we must change direction of inequality:
x > −4
−1*x < −1*−4
−x < 4
2016-08-10 3:06 pm
c
2016-08-10 3:35 pm
Ans. C.
2016-08-10 3:12 pm
x > -4
-x < 4
changing the signs reverses the inequality sign
-x < 4
changing the signs reverses the inequality sign
收錄日期: 2021-05-01 21:04:04
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160810070534AAJ5EgA