"Solve Open Sentence and Graph Solution Set On Number L

InNeedOfHelp!

New member
Joined
Feb 5, 2006
Messages
11
Should this be easy? I have 18 questions under this category, of course I will not ask anyone to answer them all for me, rather, explain to me how to do it... I just don't bloody get it!

5x<= 20 and 3<x

[2-t] >1

r<5 or 3r-8>2r-6


if anyone could just explain the above three, I'm sure I can handle the rest on my own.
 
5x<= 20
Divide by 5
x<=4 and 3<x
3<x<=4
Code:
  (3->4]

   0-*
 2 3 4 5

[2-t]>1
If t=0 [2-t]=(2)>1 yes
If t=1 [2-t]=(1)>1 no
If t=2 [2-t]=(0)>1 no
If t=3 [2-t]=(1)>1 no
If t=4 [2-t]=(2)>1 yes
Code:
  (-oo->1)and(3->oo)
----0   0-----
  0 1 2 3 4


3r-8>2r-6
Subtract 2r
r-8>-6
add 8
r>2
r<5 or r>2
Always true
Code:
     (-oo->oo)
   --------------
... 0 1 2 3 4 5 6...
 
Ummmm, I thought about saying it that way. They both say the same thing but I felt my phrasing gave a clearer picture of why it is always true. I think it is strictly a matter of opinion.
 
InNeedOfHelp! said:
I thought I had it!

-2<=x+1<4

Help!

Add -1 to each part of the inequality (to get x by itself):

-2 + (-1) <= x + 1 + (-1) < 4 + (-1)

-3 <= x < 3

I hope this helps you.
 
InNeedOfHelp! said:
I thought I had it!

-2<=x+1<4

Help!

One way to work these is to work each "side" separately. This problem can be written as
-2 <=x+1 and x+1 < 4

Now solve each part in the same way as you would solve an equation -- that is, add or subtract the same thing from both sides, then multiply or divide both sides by the same number until the variable is by itself. Remember that if you multiply or divide by a negative number, you must reverse the inequality (> becomes <, < becomes>, and so on).

 
Not sure where you got -3 nor x+1. Thaking the
5x<= 20
When you divide by 5 you get
x<=4
Now you have x by itself in both equations.
x<= 4 and
3<x
Puting them together
3 < x <=4
so on the number line it is valid between 3 and 4 with 3 not included (3 is not < 3) and 4 included (4 is = 4) so the answer is from about
3.0000001 to 4.00000 is the range where it is true. The 3 gets an empty circle and the 4 a solid circle on the line.
 
Sorry, I didn't realize that was a new problem. I assumed you were doing something I didn't understand to the only x problem we had. :oops:
-----------
Gene
 
Gotchya. Thanks Much!! I'll be back, I have a lot of work left to do, and my deadline is Friday... I'll need all the help I can get! Y'all rock! :D 8-)
 
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