## anonymous 5 years ago 2|x|+10=|x|+3

1. anonymous

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?

2. anonymous

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

3. anonymous

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

4. anonymous

so, basically, x has no solution, right?

5. anonymous

well, thanks for taking your time to help me

6. anonymous

7. anonymous

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 .

8. anonymous

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

9. anonymous

10. anonymous

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.

11. anonymous

ok, got that :)

12. anonymous

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).

13. anonymous

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!

14. anonymous

Hope the study's going well. Say hi to BMF!

15. anonymous

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

16. anonymous

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

17. anonymous

haha

18. anonymous

means BIG MF

19. anonymous

but it is just a coinsidense...

20. anonymous

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

21. anonymous

coincidence

22. anonymous

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

23. anonymous

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

24. anonymous

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

25. anonymous

Are you tested in spoken English too?

26. anonymous

Why are you being tested in English at all?

27. anonymous

fortunately, no

28. anonymous

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..

29. anonymous

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

30. anonymous

Ah, nice.

31. anonymous

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

32. anonymous

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

33. anonymous

yeah

34. anonymous

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.. :)

35. anonymous

Like what?

36. anonymous

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 :)

37. anonymous

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

38. anonymous

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..

39. anonymous

okay

40. anonymous

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..

41. anonymous

but you don't get bored with computers either

42. anonymous

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?

43. anonymous

Yes, totally. I see your point.

44. anonymous

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

45. anonymous

lol, I see a weird logic to that.

46. anonymous

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

47. anonymous

me*

48. anonymous

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

49. anonymous

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 :)

50. anonymous

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