Thread: Equalities -Need Help

Hi,

I'm curious about the question below. I felt that answer should be (a). Anyone knows?

If |a|<4 and |b|>9, then the best we can say about |a-b| is that?
(a) |a-b|<-5
(b) |a-b| > 5
(c) |a-b| <5
(d) |a-b| >13

Thanks loads,
weijing

Originally Posted by weijing85

Hi,

I'm curious about the question below. I felt that answer should be (a). Anyone knows?

If |a|<4 and |b|>9, then the best we can say about |a-b| is that?
(a) |a-b|<-5
(b) |a-b| > 5
(c) |a-b| <5
(d) |a-b| >13

Thanks loads,
weijing

An absolute value is allways positive or zero. So a) is definitely not a solution to your question.

To find the answer to the question use the numberline.

Originally Posted by weijing85

If |a|<4 and |b|>9, then the best we can say about |a-b| is that?
(a) |a-b|<-5 (b) |a-b| > 5 (c) |a-b| <5 (d) |a-b| >13

You have been told that it cannot be a).

Recall that is the distance between .
Distance is never negative.
With that in mind, which is the answer?

Hmmm...so (b) is the answer?

Wait....not (b) .... I think its (c). Pls correct me if im wrong ((:

Originally Posted by weijing85

Wait....not (b) .... I think its (c). Pls correct me if im

Let .

What is the minimum distance between those two sets?
The answer is not c).