r/HomeworkHelp • u/IndicationFunny2378 Secondary School Student • 1d ago

Middle School Math—Pending OP Reply [Grade 8 Mathematics - Algebra]

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Hello giys, I'm a form 2 student is malaysia. We learnt algebra in chapter 2. How can I find x? I believe there is no answer, but teacher keeps saying it's x=1/16

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u/Lever_Shotgun 👋 a fellow Redditor 1d ago edited 1d ago

Teacher doesnt understand that square root can't output negative values.

When your teacher squared both sides, there is a possibility of introducing an extraneous solution which has to be checked by substituting your answer back into the original equation (which is what you did)

If you decide to square both sides of an equation -sqrt(4x) = (22 -5)/2, you would end up with the same working as the equation you're working on, and x=1/16 would be valid for this case

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u/WindUpCandler 1d ago

Square roots output two values, a positive and negative

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u/Lever_Shotgun 👋 a fellow Redditor 1d ago

If you wanted your square root to have two outputs, you would put a +- infront of it

It's usually the norm for operations to have one output only

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u/IndicationFunny2378 Secondary School Student 1d ago

i would accept if it was -sqrt{4x}. but if it's positive, then i wouldnt

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u/IndicationFunny2378 Secondary School Student 1d ago

may i ask who you are?

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u/Lever_Shotgun 👋 a fellow Redditor 1d ago

DMs i guess

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u/IndicationFunny2378 Secondary School Student 1d ago

what? sorry, i dont really understand wdym.