Question

2|x|+10=|x|+3

Answer 1

I tried to solve it, but I get to |x|=-7
as far as I remember, absolute value laws say that if absolute value |x| results to a negative number in an equation, then x does not have solution.
Am I right or am I forgeting something?

Answer 2

|x|= -x if x<0 &
=x if x>=0

Answer 3

yes i got the same thing :) |x|=-7

Answer 4

so, basically, x has no solution, right?

Answer 5

well, thanks for taking your time to help me

Answer 6

your welcome oktal !

Answer 7

oktal, you're right when you get -7...this system has no solution...that's a solution in itself :) Also, you can see this if you plot \[y=2|x|+10\]and\[y=|x|+3\]They'll never meet at a point, which means there'll never be a x-value that will give you a y-value (and therefore solution) they will share .

Answer 8

so, basically, if |x| = negative number, x ALWAYS has no solution....

Answer 9

your explanation is good

Answer 10

Yeah, well, you can check also by using the definition of |x|, which is\[|x|=\sqrt{x^2}\]If you use that definition, you'll end up with\[2\sqrt{x^2}+10=\sqrt{x^2}+3 \rightarrow \sqrt{x^2}=-7\]which is rubbish IF x is real.

Answer 11

ok, got that :)

Answer 12

AND...if you continue to assume there is a solution, then after squaring both sides,\[x^2=49 \rightarrow x= \pm 7\]If you now sub. each of these results into the left-hand side, you get\[2|\pm 7|+10=24\]and in the right:\[|\pm 7|+3=10\]which means the LHS and RHS do not agree...i.e. you end up with a contradiction if you assume this thing has a solution. You have no option, the, but to reject the assumption that there is a solution (since that's the only assumption you've made).

Answer 13

Bit more complicated than needed, but |x| is never less than 0, so |x|=-7 should be a red flag.

Also - PLOT IT if you have time!

Answer 14

Hope the study's going well.

Say hi to BMF!

Answer 15

=D everything is going fine.. and yeah, I will say Hi to BMF

Answer 16

btw, some other ppl use BMF to represent a swear word combo, I think you know what that is :)

Answer 17

haha

Answer 18

means BIG MF

Answer 19

but it is just a coinsidense...

Answer 20

Since your exam covers English, if see a mistake, do you want me to correct it?

Answer 21

coincidence

Answer 22

:) thanks, I am really bad at spellings and grammar... still learning

Answer 23

pfft, you're not bad at all! I only saw one thing!

Answer 24

well, my written English might be OK, but my spoken is worse because of my accent

Answer 25

Are you tested in spoken English too?

Answer 26

Why are you being tested in English at all?

Answer 27

fortunately, no

Answer 28

because this university is located in Non-English speaking country, Finland, hence they need to be sure that all students know English as education in this uni is in Eng..

Answer 29

many ppl from all over the world come here.. from China, japan, USA, UK...

Answer 30

Ah, nice.

Answer 31

eventhough the exams are on 12th, which is in few days, I will only get the results in June.

Answer 32

I've been through something like that. It's hell. Are the exams only run once per year?

Answer 33

yeah

Answer 34

and hell, now I dont even know if I did the best choice by choosing Media Engineering ... I am starting to think maybe I should have taken something else.. :)

Answer 35

Like what?

Answer 36

like some more technical field, like Computer Science, or even Electronics Engineering..
because I have been doing CS and electronics all my life, but then I chose Media Engineering as it pays better :)

Answer 37

What do you even do in media engineering? Why don't you get into computer science or computer engineering?

Answer 38

well, in media engineering you do stuff like special effects for movies, you work in music studios with equipment, you build/manage TV studio equipment, you can also get into advertisement, like design TV advertisement videos... I think you get an idea, Media Engineering deals with visual presentation of info/entertainment.... something like that..

Answer 39

okay

Answer 40

and the good thing about it is that every time the job is different, so you dont really get bored, it involves lots of creativity..

Answer 41

but you don't get bored with computers either

Answer 42

yeah, if I do what ever I want with them I dont get bored, but if I had to write code for some company day after day, sont you think it can get monotonous?

Answer 43

Yes, totally. I see your point.

Answer 44

so that is why I decided to go with something I barely know..

Answer 45

lol, I see a weird logic to that.

Answer 46

and, I like challenges, so it is kind of exciting to apply for something I know nothing about... gives my a feeling of challenge, uncertainity, mental adventure LOL =D

Answer 47

me*

Answer 48

So you finished studying for the day? Isn't like 10:25 am or something over there?

Answer 49

yeah, 10:25... and actually I am solving problems right now... so i do two things at the same time, helps to develop my multitasking skills :)

Answer 50

Well, I have my own stuff that needs to get done :( Boring...so, study well...see you later :D