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Mathematics 8 Online
OpenStudy (anonymous):

.

Vocaloid (vocaloid):

well, sometimes when you solve an equation and end up with an "x" value, the x-value doesn't make the equation true when you plug it back in, because it isn't in the domain of the original function in short: an extraneous solution is like a "fake" solution that you find that doesn't make the equation true when you plug it back in

Vocaloid (vocaloid):

so, looking at our problem, do you know how to solve for x?

OpenStudy (anonymous):

can you subtract 1/(x+4)?

OpenStudy (anonymous):

i like how i tag @vocaloid and3 other people come xd

Vocaloid (vocaloid):

well, technically yes, but in this case we want to try a different method this equation doesn't have any real (non-extraneous solutions) but we want to find the "fake" extraneous one

OpenStudy (anonymous):

okay then idk

Vocaloid (vocaloid):

so, we multiply everything by (x+4) to get rid of the denominator

OpenStudy (anonymous):

oohhhhh okay

Vocaloid (vocaloid):

that gives us 1 + (1/2)(x+4) = 1 can you try solving for x now?

OpenStudy (anonymous):

First can you subtract the one?

Vocaloid (vocaloid):

yes, just treat it like a normal equation

OpenStudy (anonymous):

how do you multiply 1/2 by x+4

Vocaloid (vocaloid):

you don't have to after you subtract 1 from both sides, we have (1/2)(x+4) = 0 now divide both sides by (1/2), what do you get?

OpenStudy (anonymous):

x+4=0 lol sorry i knew that i don't know why i forgot You get -4 right?

OpenStudy (anonymous):

so its B?

Vocaloid (vocaloid):

nope, not B, hang with me for a sec ;) x = -4 is called an "extraneous solution" although we got x = -4 as an answer, when we plug x = -4 back into the original equation, we can see that the denominator of the first fraction becomes 0, x = -4 isn't a "real" solution

OpenStudy (anonymous):

oh A

Vocaloid (vocaloid):

right-o

OpenStudy (anonymous):

can u help me with a few more?

Vocaloid (vocaloid):

sure, post a new q and tag me

OpenStudy (anonymous):

k

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