Ask your own question, for FREE!
Mathematics 10 Online
OpenStudy (anonymous):

someone please help. Which conjunction or disjunction is equivalent to the given absolute value inequality? |x + 2| < 18 a. x + 2 > 18 or x + 2 < 18 b. x + 2 > 18 and x + 2 < 18 c. x + 2 < 18 or x + 2 > 18 d. x + 2 < 18 and x + 2 > 18

OpenStudy (ybarrap):

\(|x+2|<18\\\implies-18<x+2<18\\\implies-18-2<x<18-2\\\implies-20<x<16\) So, \(|x+2|<18\implies x+2 < 18 \) and \( x+2 > -18\) I don't see that option among yours.

OpenStudy (anonymous):

the negitives didnt go tthru. u are correct :)

OpenStudy (ybarrap):

Ok.

OpenStudy (anonymous):

thanks:)

OpenStudy (ybarrap):

You're welcome :)

OpenStudy (ybarrap):

You should close this one and give me a medal or something, otherwise people will just come and and look at this problem and see that it is solved. It's up to you ;)

OpenStudy (anonymous):

lol how do u give medals?

OpenStudy (ybarrap):

When you click on "Best Response" that's a medal. You just gave me a one. :)

OpenStudy (anonymous):

ohh hah sweet can u help my with another similar problem but walk me thru it pleaese?

OpenStudy (ybarrap):

But if you decide later that you don't like me, you can take it back and give it to someone else :( But you won't do that, right?

OpenStudy (anonymous):

haha i will not :)

OpenStudy (ybarrap):

I'm here for you, at least for a little while

OpenStudy (anonymous):

okay thanks so much :))))

OpenStudy (ybarrap):

k, shoot

OpenStudy (anonymous):

okay l x l < 3

OpenStudy (anonymous):

how would u do that if ur solving for the same thing as the first problem?

OpenStudy (ybarrap):

If I need to leave, feel free to send me a note \(|x|<3\) means this: \(-3 < x < 3\). It's THAT easy! Now, \(-3 < x < 3\) means: \(x < 3 \) and \(x > -3\). ALWAYS the same pattern.

OpenStudy (ybarrap):

So if you had something else other than "x", just replace EVERYTHING between the "| |" where I have "x" above and repeat. Say you had |x +2| < 3, this means: $$ |x+2| < 3 -3 < x+2 < 3 $$ Notice when I put the -3 there I REMOVED the "| |" part?

OpenStudy (ybarrap):

Let me rewrite that equation: $$ |x+2| < 3\\ \text{ means}\\ -3 < x+2 < 3 $$

OpenStudy (anonymous):

thankss so muchh :))

OpenStudy (ybarrap):

Does it make sense? Really?

OpenStudy (anonymous):

yesss

OpenStudy (ybarrap):

k

OpenStudy (anonymous):

okay im having trouble with another one but the multiple choice dosnt look formilar.. its in a different format :(

OpenStudy (anonymous):

|2x + 3| < 11

OpenStudy (anonymous):

and the choices areee...

OpenStudy (anonymous):

OpenStudy (anonymous):

ok well that didnt work.. imma try to type it

OpenStudy (anonymous):

a. xE (-7,4)

OpenStudy (ybarrap):

k

OpenStudy (anonymous):

b. (-14,8)

OpenStudy (ybarrap):

Link above says "access denied, you need super human capabilities to access" or something like that

OpenStudy (anonymous):

c. (11,infinity)

OpenStudy (anonymous):

lol iknow thats why im just typing it :0

OpenStudy (anonymous):

or d. (-8,11)

OpenStudy (ybarrap):

|2x + 3| < 11 Ok, imma let you do this What does it mean and REALLY try please!! And don't get mad at me an revoke my medal

OpenStudy (anonymous):

x is less than 11.. ? right

OpenStudy (ybarrap):

2x + 3 < 11 That's the 1st step, what else?

OpenStudy (anonymous):

do u have to do 3-3 and 11-3? .. or no

OpenStudy (ybarrap):

Not yet

OpenStudy (anonymous):

o

OpenStudy (ybarrap):

2nd step: -11 < 2x + 3 See that? Same pattern.

OpenStudy (ybarrap):

Where did the -11 come from?

OpenStudy (anonymous):

because u subtracted it from 11

OpenStudy (ybarrap):

Whenever you have something like |blah blah blah| < something This means - something < blah blah blah AND blah blah blah < something

OpenStudy (anonymous):

ohh i get it now

OpenStudy (ybarrap):

So, "something" here is "11"

OpenStudy (ybarrap):

That's why the -11

OpenStudy (anonymous):

so it became "-something"

OpenStudy (ybarrap):

yay!!!!

OpenStudy (anonymous):

whats the next step

OpenStudy (ybarrap):

ok So we have $$ |2x + 3|<11\\ -11 < 2x+3 < 11 $$ Now we need to rearrange the blah blah part so that we only have "x" by itself there. We do that by 1st subtracting -3 from -11 and from 2x +3 and from 11 like this: \(-11 -3< 2x+3 -3< 11-3\) This gets rid of the 3 in the blah blah part of the equation

OpenStudy (ybarrap):

Now we have: -14 <2x<8

OpenStudy (ybarrap):

See that?

OpenStudy (anonymous):

yesss.

OpenStudy (ybarrap):

But we don't have x by itself yet. how do we make it so x is there alone in the center. We have 2x and we want to make it "x" alone. What do we need to do?

OpenStudy (ybarrap):

What can we divide 2x by to get just "x"?

OpenStudy (anonymous):

2

OpenStudy (anonymous):

do u do that to -4 and 8 too?

OpenStudy (ybarrap):

yep. BUT, whatever we do to 2x we also must do to those endpoints, which we are calling "something" I see you already saw that coming!! Nice. Nice!!!

OpenStudy (ybarrap):

Do it!!

OpenStudy (anonymous):

:) haha but how do u solve for y?

OpenStudy (anonymous):

then i have -2<x<4

OpenStudy (ybarrap):

Finish the problem! Your are practically there. No, don't solve for anything, just divide

OpenStudy (anonymous):

--^

OpenStudy (ybarrap):

-14 <2x<8 Dividing EVERYTHING by 2, we get -14/2 < 2x/2 < 8/2 Please, you can do this... what ya get?

OpenStudy (anonymous):

oops i did -4/2 instead of -14

OpenStudy (ybarrap):

well?

OpenStudy (anonymous):

-7<x<4

OpenStudy (ybarrap):

yaaaay!!!

OpenStudy (ybarrap):

So this means what?

OpenStudy (ybarrap):

something is less than something AND -something is less than something... Help me...

OpenStudy (anonymous):

-7, 4 !! :D

OpenStudy (anonymous):

yesss omg thank u so much :D

OpenStudy (ybarrap):

Yea, -7 < x AND x < 4, Right?

OpenStudy (ybarrap):

you get a medal!!

OpenStudy (anonymous):

right, thanks so much. ur an awesome teacherrrrr!:)

OpenStudy (ybarrap):

It's slow to learn but better to do it yourself and understand

OpenStudy (ybarrap):

ur awesome, too

OpenStudy (anonymous):

yeah.. the school that im attending is k12 and i pretty much have to teach myself everything and it sucksks :(

OpenStudy (ybarrap):

It was a pleasure helping you

OpenStudy (anonymous):

if i ever need help in the future can i messga u ?

OpenStudy (anonymous):

:)

OpenStudy (ybarrap):

yep, anytime

OpenStudy (anonymous):

sweet :D

OpenStudy (ybarrap):

sweet

OpenStudy (ybarrap):

take care

OpenStudy (anonymous):

you tooo!

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!