Which of the following is a solution of the inequality

eddy2017

eddy2017

Elite Member
Joined
Oct 27, 2017
Messages
2,525
Hi, would you drop a hint about how to continue to solution here?. I'm stuck there. Or, can't that be simplified any further?
[math]-3 <2x+1<5[/math]After computing I get
-2<x<2

Thanks,
 
Fine, after computing you got -3 < 2x+1 < 5. Is there any chance that you show us your work? Why are you questioning your solution?
You say that you are stuck, yet you found that x is between -2 and 2. if you did not want to find what x was between, then can you tell us exactly what you wanted to find? For example, 2x+2 is between -2 and 6.
 
I'm stuck because the answer I get to is not listed in the choices given
Choices
-2
0
2
4
I have -2 at the beginning of the inequality so I would have gone for -2 but just don't want to do that and have no firm reason behind it.
 
Think I got it. I didn't even have to compute anything. Just try every choice given for x

[math]-3<2(0)+1<5[/math][math]-3<1<5[/math]So the answer is 0 because the others don't give a true statement.
 
Okay, I am confused now. Isn't the answer 0 then?.

Thstcwas what I got stuck at first. Because I thought I had to solve the inequality. But when I looked at the choices they all had one number in each choice and I was getting not a number but this:
-2<x<2
-2 nope.
2 nope
4 nope
0 checks out!
0 is less than 2 but greater than -2
Got it now
Thanks to all.
 
eddy2017 said:
Hi, would you drop a hint about how to continue to solution here?. I'm stuck there. Or, can't that be simplified any further?
[math]-3 <2x+1<5[/math]After computing I get
-2<x<2

Thanks,
Click to expand...
Did you copy the problem correctly? It sounds very strange. The solution of that compound inequality is a range of values (I would assume reals), not a single number. If the question was actually about a single number, I think it should've asked not "which is the solution?", but "what number satisfies the inequality?"
 
This is the problem when the original problem is not given word for word. I can think of two wordings, one poor and one fine, that make 0 a sensible answer.

Poor wording: "Given [imath]-3 < 2x + 1 < 5[/imath], which of the following is x."

Good wording: "Given [imath]-3 < 2x + 1 < 5[/imath], which of the following is a possible value for x."
 
lev888 said:
Did you copy the problem correctly? It sounds very strange. The solution of that compound inequality is a range of values (I would assume reals), not a single number. If the question was actually about a single number, I think it should've asked not "which is the solution?", but "what number satisfies the inequality?"
Click to expand...
Yes, that is what confused me. I know how to solve compound inequalities but when I got to the end I saw that I had no number but just a simplified inequality.
 
BigBeachBanana said:
Why don't you just screenshot your problem for your threads? Save you some time typing out the question and potential errors.
Click to expand...
You're right about that. Thanks.

JeffM said:
A solution may mean one of many. It is a fair question. It was not your math that was faulty, but your understanding of the problem.
Click to expand...
Yes!

JeffM said:
This is the problem when the original problem is not given word for word. I can think of two wordings, one poor and one fine, that make 0 a sensible answer.

Poor wording: "Given [imath]-3 < 2x + 1 < 5[/imath], which of the following is x."

Good wording: "Given [imath]-3 < 2x + 1 < 5[/imath], which of the following is a possible value for x."
Click to expand...
Right.
 
eddy2017 said:
I'm stuck because the answer I get to is not listed in the choices given
Choices
-2
0
2
4
I have -2 at the beginning of the inequality so I would have gone for -2 but just don't want to do that and have no firm reason behind it.
Click to expand...
I am getting tired of you (and many others) not giving the complete problem. How on earth can one know that there are choices to this problem and know what the choices are?!!!!

The problem you are having in not knowing which choice to pick is because you do not know how to read your answer. As I always say, being able to solve a problem is one thing but knowing what the answer is, is something different.

a<x<b means that x is any number between a and b (excluding both endpoints)
a< x < b means that x is any number between a and b (including a)
a<x<b means that x is any number between a and b (including b)
a< x <b means that x is any number between a and b (including a and b)

Now -2 < x <2 means x is any number between - 2 and 2 excluding -2 and 2.
Just go to your choices and pick an answer that contains a number between -2 and 2!!! Is that so hard?
 
Steven G said:
I am getting tired of you (and many others) not giving the complete problem. How on earth can one know that there are choices to this problem and know what the choices are?!!!!

The problem you are having in not knowing which choice to pick is because you do not know how to read your answer. As I always say, being able to solve a problem is one thing but knowing what the answer is, is something different.

a<x<b means that x is any number between a and b (excluding both endpoints)
a< x < b means that x is any number between a and b (including a)
a<x<b means that x is any number between a and b (including b)
a< x <b means that x is any number between a and b (including a and b)

Now -2 < x <2 means x is any number between - 2 and 2 excluding -2 and 2.
Just go to your choices and pick an answer that contains a number between -2 and 2!!! Is that so hard?
Click to expand...
You're right!. I have to look at the answer choices. Sometimes you can tell by just looking at them. Not many times, but this one here is an example
Thanks!
 
eddy2017 said:
You're right!. I have to look at the answer choices. Sometimes you can tell by just looking at them. Not many times, but this one here is an example
Thanks!
Click to expand...
You missed my whole point. Finding out that -2<x<2 or |x|<2 is one fine way towards finding the answer. Now that you know that x is between -2 and 2 you can now look at the choices!
 
Steven G said:
You missed my whole point. Finding out that -2<x<2 or |x|<2 is one fine way towards finding the answer. Now that you know that x is between -2 and 2 you can now look at the choices!
Click to expand...
It is always good to solve the inequality but don't forget that in a timed test I need to save all the time I can. And this question is one type of question that can be solved with just one look at the inequality and a quick peek at the choices.
 
You must log in or register to reply here.
Top