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Mathematics 7 Online
OpenStudy (mtwizzle420):

Identify any extraneous solutions @YOLO_KING

OpenStudy (mtwizzle420):

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OpenStudy (yolo_king):

Do you have choices?

OpenStudy (mtwizzle420):

Yep hold on a sec :)

OpenStudy (yolo_king):

\[x=\sqrt{4+12}\] So I got x= 4

OpenStudy (yolo_king):

Because 4 + 12 = 16 and \[\sqrt{16}= 4\] So x= 4

OpenStudy (mtwizzle420):

A.) 2 is a solution to the original equation. The value -6 is an extraneous solution. B.) 6 and -2 are solutions C.) 6 and 2 are both extraneous solutions D.) 6 is a solution to the original equation. The value of -2 Is an extraneous solution

OpenStudy (yolo_king):

Wait im comfused so are these choices part of the x=\[\sqrt{4+12}\] problem?

OpenStudy (mtwizzle420):

Yep its said identify any extraneous solutions

OpenStudy (yolo_king):

hmmmmm... I am not sure about this one let me get some help

OpenStudy (mtwizzle420):

Okay the last question is like this to just a heads up :)

OpenStudy (yolo_king):

@campbell_st Could you help out?

OpenStudy (yolo_king):

kk

OpenStudy (yolo_king):

I have no idea about this one :/

OpenStudy (campbell_st):

well the equation would appear to be (x -6)(x + 2) = 0 or \[x^2 - 4x - 12 = 0\] so is the problem \[x = \sqrt{4x + 12}\]

OpenStudy (mtwizzle420):

Yes it is

OpenStudy (campbell_st):

ok... so yo solve it square both sides of the equation and you get \[x^2 = 4x + 12\] subtract 4x and 12 from both sides and its \[x^2 - 4x - 12 = 0\] this can be solved by factoring (x + 2)(x - 6) = 0 which gives -2 and 6 as solutions now substitute these into the original question to see if anything doesn;t work so \[x = \sqrt{4x + 12}~~ x = 2~~~then~~~ 2 = \sqrt{4 \times 2 + 12}\] does that work...? and then repeat it with x = 6 \[6 = \sqrt{4 \times 6 + 12}\] does that work... an extraneous solution is one that may be a solution, but when its tried in the original equation it doesn't work

OpenStudy (mtwizzle420):

Thank you!

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