Page 1 of 2 12 LastLast
Results 1 to 15 of 17
Like Tree2Thanks

Math Help - Inequalities HELP!!

  1. #1
    Newbie
    Joined
    Aug 2012
    From
    Michigan
    Posts
    15

    Inequalities HELP!!

    Need Help!!! This is not for a graded quiz. Im trying to tutor my son but Im no math wiz myself and need to figure out the correct answers so that I know when I try to help him!!!

    Question 1
    Which of the following is equivalent to |4x + 5| = 88?
    -4x + 5 = 88
    4x + 5 = -88
    4x + 5 = 88
    4x + 5 = 88 or 4x + 5 = -88



    Question 2
    Solve |6x 5| = 25.
    {5, -5}
    {5, -10/3}
    {-25, 25}
    {10/3, -5}



    Question 3
    Which statement has the solution shown on the number line?

    |x + 1| = 4
    |x 1| = 4
    |x| = 3
    none of the above



    Question 4
    Which statement is equivalent to |3x + 7| ≤ 30?
    3x + 7 ≤ 30 or 3x + 7 ≥ -30
    -30 ≤ 3x + 7 ≤ 30
    3x + 7 ≤ 30
    3x = 7 ≤ -30



    Question 5
    Solve |x+5| < 9.
    {x| x < 4 or x > -14}
    {x| x < 4 or x > -4}
    {x| -14 < x < 4}
    {x| -4 < x < 4}



    Question 6
    Which inequality has the solution shown on the number line?

    |4 x| ≤1
    |x 4| ≤ 1
    |x + 2| ≥ 5
    |x + 2| ≥ 7




    Question 7
    Which statement is equivalent to |x + 9| > 15?
    x + 9 > 15
    x + 9 < -15
    x + 9 > 15 or x + 9 < -15
    -15 < x + 9 < 15



    Question 8
    Solve |6x + 8| > 4.
    {x| -4 < x < 4}
    {x| -2 < x < -2/3}
    {x| x > -2 or x < -2/3}
    {x| x > -2/3 or x < -2}



    Question 9
    Which of the following has the solution shown on the number line?

    |x + 3| ≤ 2
    |x 3| ≤ 2
    |x + 3| ≥ 2
    |x 3| ≥ 2



    Question 10
    What is the solution of |x + 3| > -2?
    x > 1 or x < -5
    -5 < x < 1
    all real numbers
    no solution
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,614
    Thanks
    1581
    Awards
    1

    Re: Inequalities HELP!!

    Quote Originally Posted by zales127 View Post
    Need Help!!! This is not for a graded quiz. Im trying to tutor my son but Im no math wiz myself and need to figure out the correct answers so that I know when I try to help him!!!

    Question 1
    Which of the following is equivalent to |4x + 5| = 88?
    -4x + 5 = 88
    4x + 5 = -88
    4x + 5 = 88
    4x + 5 = 88 or 4x + 5 = -88



    Question 2
    Solve |6x 5| = 25.
    {5, -5}
    {5, -10/3}
    {-25, 25}
    {10/3, -5}



    Question 3
    Which statement has the solution shown on the number line?

    |x + 1| = 4
    |x 1| = 4
    |x| = 3
    none of the above



    Question 4
    Which statement is equivalent to |3x + 7| ≤ 30?
    3x + 7 ≤ 30 or 3x + 7 ≥ -30
    -30 ≤ 3x + 7 ≤ 30
    3x + 7 ≤ 30
    3x = 7 ≤ -30



    Question 5
    Solve |x+5| < 9.
    {x| x < 4 or x > -14}
    {x| x < 4 or x > -4}
    {x| -14 < x < 4}
    {x| -4 < x < 4}



    Question 6
    Which inequality has the solution shown on the number line?

    |4 x| ≤1
    |x 4| ≤ 1
    |x + 2| ≥ 5
    |x + 2| ≥ 7




    Question 7
    Which statement is equivalent to |x + 9| > 15?
    x + 9 > 15
    x + 9 < -15
    x + 9 > 15 or x + 9 < -15
    -15 < x + 9 < 15



    Question 8
    Solve |6x + 8| > 4.
    {x| -4 < x < 4}
    {x| -2 < x < -2/3}
    {x| x > -2 or x < -2/3}
    {x| x > -2/3 or x < -2}



    Question 9
    Which of the following has the solution shown on the number line?

    |x + 3| ≤ 2
    |x 3| ≤ 2
    |x + 3| ≥ 2
    |x 3| ≥ 2



    Question 10
    What is the solution of |x + 3| > -2?
    x > 1 or x < -5
    -5 < x < 1
    all real numbers
    no solution
    Do not post a whole wish list of problems.
    Usually no more than max of three.
    Also include some of your own effort.
    This is not a free homework service. It is a help service.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Aug 2012
    From
    Michigan
    Posts
    15

    Re: Inequalities HELP!!

    Thats the problem..Id LOVE to give some effort..If I even knew where to begin I wouldnt be here.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,614
    Thanks
    1581
    Awards
    1

    Re: Inequalities HELP!!

    Quote Originally Posted by zales127 View Post
    Thats the problem..Id LOVE to give some effort..If I even knew where to begin I wouldnt be here.
    Do you have a textbook? Do you have class notes ?
    If not, why not?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Aug 2012
    From
    Michigan
    Posts
    15

    Re: Inequalities HELP!!

    My sons algebra teacher quit at the beginning of the year. He has struggled in math since he began school and unfortunately Im not much help. The school went through 11 substitutes in 1 year. The substitutes that they had bounced all over and no one really cared about the kids since it was a temporary job. 62% off the freshman class failed Algebra 1. In order to move on they have to take an online course for math that basically has a 5 minute tutorial on each subject. BUT if you dont understand the basics from subject to subject your pretty much screwed..which is where have 11 substitutes in 1 year left most of the kids!
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,614
    Thanks
    1581
    Awards
    1

    Re: Inequalities HELP!!

    This is against our general policy. We are not suppose to do tutorials.
    Say K\ge 0.
    \text{If }|ax+b|=K\text{ then }ax+b=K\text{ OR }ax+b=-K

    \text{If }|ax+b|\le K\text{ then }ax+b\le K\text{ AND }ax+b\ge -K

    \text{If }|ax+b|\ge K\text{ then }ax+b\ge K\text{ OR }ax+b\le -K


    EXAMPLES
    |3x+2|=5 means x=1\text{ OR }x=-\frac{7}{3}

    |4x-5|\le 7 means -\frac{1}{2}\le x \le 3

    |x+1|\ge 2 means x\le -3\text{ OR }1\le x

    BTW: If I were you I would file a lawsuit against the school system.
    Last edited by Plato; August 25th 2012 at 02:54 PM.
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Newbie
    Joined
    Aug 2012
    From
    Michigan
    Posts
    15

    Re: Inequalities HELP!!

    Thank you!! This helps tremendously. We are in the works of taking action against the school right now with all the other parents.
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Newbie
    Joined
    Aug 2012
    From
    Michigan
    Posts
    15

    Re: Inequalities HELP!!

    So if I have the problem |6x 5| = 25


    x=6 or 30/36...which I have a feeling is completely wrong
    Follow Math Help Forum on Facebook and Google+

  9. #9
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,614
    Thanks
    1581
    Awards
    1

    Re: Inequalities HELP!!

    Quote Originally Posted by zales127 View Post
    So if I have the problem |6x 5| = 25
    x=6 or 30/36...which I have a feeling is completely wrong
    6x-5=25 so 6x=30 or x=5
    OR
    6x-5=-25 so 6x=-20 or x=\frac{-20}{6}
    Follow Math Help Forum on Facebook and Google+

  10. #10
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,519
    Thanks
    1404

    Re: Inequalities HELP!!

    Think of the absolute value as the "size" or "distance" of a number. For example |-4| = 4, since it is four units away from 0 on the number line, and |7| = 7, since it is 7 units away from the number line.

    Also, in most of your questions, you have asked "which of these solutions is shown on the number line", without posting the number line in question...
    Follow Math Help Forum on Facebook and Google+

  11. #11
    Newbie
    Joined
    Aug 2012
    From
    Michigan
    Posts
    15

    Re: Inequalities HELP!!

    Thank you Prove It and Plato..I guess Im confused as to where - are the same. Like in this problem Which of the following is equivalent to |x - 2| = 6?
    These are the options that I narrowed it down to..but I cant figure out where the - comes in.

    x 2 = 6
    x 2 = 6 or x 2 = -6
    By working the problem I think the answer is x-2=6 however it could be x-2=6 or x-2=16
    Follow Math Help Forum on Facebook and Google+

  12. #12
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,519
    Thanks
    1404

    Re: Inequalities HELP!!

    Quote Originally Posted by zales127 View Post
    Thank you Prove It and Plato..I guess Im confused as to where - are the same. Like in this problem Which of the following is equivalent to |x - 2| = 6?
    These are the options that I narrowed it down to..but I cant figure out where the - comes in.

    x 2 = 6
    x 2 = 6 or x 2 = -6
    By working the problem I think the answer is x-2=6 however it could be x-2=6 or x-2=16
    You are correct that it's both x - 2 = 6 and x - 2 = -6. That means x = 8 or x = -4.

    This is easy to prove if you draw a number line and observe that 8 and -4 are both 6 units away from 2.
    Thanks from zales127
    Follow Math Help Forum on Facebook and Google+

  13. #13
    Newbie
    Joined
    Aug 2012
    From
    Michigan
    Posts
    15

    Re: Inequalities HELP!!

    Ok..i think Im slowly getting it. What does it mean when there is a line under < or >?
    Follow Math Help Forum on Facebook and Google+

  14. #14
    Newbie
    Joined
    Aug 2012
    From
    Michigan
    Posts
    15

    Re: Inequalities HELP!!

    Inequalities HELP!!-line.jpg

    The reason I asked the above question is because it states "Which of the following has the solution shown on the number line?

    The answer that I came up with was |x + 1| ≥ 7
    Follow Math Help Forum on Facebook and Google+

  15. #15
    Newbie
    Joined
    Aug 2012
    From
    Michigan
    Posts
    15

    Re: Inequalities HELP!!

    Click image for larger version. 

Name:	line.jpg 
Views:	2 
Size:	34.0 KB 
ID:	24603

    The reason I asked the above question is because it states "Which of the following has the solution shown on the number line?

    The answer that I came up with was |x + 1| ≥ 7 (Sorry the picture in my above post was really tiny..you have to click on the image)
    Follow Math Help Forum on Facebook and Google+

Page 1 of 2 12 LastLast

Similar Math Help Forum Discussions

  1. Inequalities
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: September 9th 2010, 12:10 AM
  2. Please help with inequalities
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: February 19th 2010, 01:03 PM
  3. Help with inequalities
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 18th 2010, 05:30 AM
  4. Help me! inequalities
    Posted in the Algebra Forum
    Replies: 1
    Last Post: August 31st 2008, 07:56 PM
  5. pdf about inequalities
    Posted in the Math Forum
    Replies: 0
    Last Post: August 26th 2008, 04:09 AM

Search Tags


/mathhelpforum @mathhelpforum