Radical problem issue

[gcooper]

square root of x^2 - 8x + 16

I tried to approach it like this:

4+x sqrroot(-8x)

4+x sqrroot (-4 * 2x)

2+4+x sqrroot(2x)

6x sqrroot(2x)

But the actual correct answer is: x - 4

And aside from the usual "where did I go wrong" question, another question would be: " How should I handle negative numbers in square roots, since a square root can't output negative values? Should I just consider the negative term, positive?"

 

[gcooper]

x^2 - 4x - 4x + 16

If I wanted to remove the -4xes that are under the square root, what would I get outside? I see you used factoring to prove that the actual answer works, but it really did not clear the fog for me.

 

[pka]

x^2 - 4x - 4x + 16
If I wanted to remove the -4xes that are under the square root, what would I get outside? I see you used factoring to prove that the actual answer works, but it really did not clear the fog for me.

Do you understand that \(\displaystyle \sqrt{a^2}=|a|~?\) If not then that is your problem.

\(\displaystyle \sqrt{x^2-8x+16}=|x-4|.\)

 

[gcooper]

got it now.