Question 479289
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Hi. Here is the problem I'm stuck on. The math problem says to simplify the expression.

{{{ sqrt 864x^2 }}}

I know the square root of 864 is 12 sqrt 6, but I don't know what to do with the x^2.
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The answers in the posts by tutors  @Theo and  @MathLover1,  giving   12x*sqrt(6),   both are incorrect.


The correct answer is    12*|x|*sqrt(6).



The  @Theo's answer and the  @MathLover1's answer are valid only for non-negative  'x'.


For negative values of  'x'  they are wrong.



But in the original expression,  'x'  can be negative,  too.



In this case,  the @Theo's answer and the @MathLover1 answer  both are  INCORRECT, 

while my answer works for both cases non-negative and negative values of  'x',

so,  it is universally correct.



It is very important to know what is a correct expression for   {{{sqrt(x^2)}}}.


It is not  'x',  as  99%  of people and  90%  of teachers and tutors think.  



                The correct expression is  |x|.  



99%  of students of middle school and of high school don't know it.


For you,  reading this my post is the rare and the happy opportunity to learn the truth.