Question

K im confused.....

|2x + 5| = x + 1

x= -4 OR x= -2

Answer 1

Wrong

Answer 2

If I'm doing |2(-4) + 5| doesnt this equal |-3| and it becomes a positive 3?

Answer 3

many people today are asking absolute values question
what's going on. my head is going dizzy with this hehehe

Answer 4

i don't what you are trying to do here
where did you come up with x=-4 or x=-2
did you solve the equation first?

Answer 5

You solve for it first... and then you plug it in

Answer 6

ummm to me x=-4 and x-2 both wont work but i may be wrong

Answer 7

okay then you must have done it wrong, because the two answer are not good

Answer 8

no thats the right answer when you solve for x

Answer 9

i already know it doesnt work but i need to know the process

Answer 10

no it is not the right answer! check you steps

Answer 11

hey don't disrespect people, respect yourself pls

Answer 12

i'm confused

Answer 13

so @yomamabf show us the work you did

Answer 14

@swissgirl what do you mean by x + 1 is greater than or equal to 0

Answer 15

wait can you just tell me if its possible though? if |2x + 5| equals positive 3 if x is -4

Answer 16

yes

Answer 17

and that was an observation i made
basically x must equal or be greater than -1

Answer 18

why -1?

Answer 19

oh okay so i was right it is positive 3 because of the absolute value

Answer 20

ehhh i know how you got -4 and -2

Answer 21

yea i solved for x

Answer 22

yup but for some reason when you plug it back in it ... it doesnt add up

Answer 23

yea its not supposed to i just need to understand why

Answer 24

most likely cuz of the x on the other side

Answer 25

hey it doesnt equal each other because its a 3 = -3? right?

Answer 26

Yup :)

Answer 27

thanks love

Answer 28

no problem hun

Answer 29

if i plug in -2 to -x-1 how does it come out to be -1 i'm confused

Answer 30

oh oops nvm

Answer 31

are you solving
|2x + 5| = x + 1

?

Answer 32

no nvm i got it thanx

Answer 33

No worries! I am not sure how you have worked it but squaring both sides and solving the quadratic seems to be one way to approach this. Also don't forget to check your solutions everytime you square because, squaring increases the degree of polynomial and the end result is increase in number of fake solutions (I see you're checking your answers already :))

Answer 34

we didnt solve it ... we just showed how x=-2 and x=-4 will not satisfy the equations.
Are there any other options

Answer 35

Like any other methods of solving this absolute value equation?

Answer 36

I like squaring both sides because I don't have to worry about the messy cases and + and - signs

Answer 37

Thanks :)

Answer 38

Without squaring :
|2x + 5| = x + 1

gives two cases :
2x+5 = x+1 OR 2x+5 = -(x+1)
x = -4 OR x = -2

Answer 39

not bad at all !

Answer 40

thanks a lot for your help!

Answer 41

however both are extraneous solutions because when you plug them back in the original equaiton, they don't satisfy

Answer 42

don't mean to be repetitive, just saying for completeness :)

Answer 43

yap gotcha thanks!

Answer 44

hahaha :D