@hartnn
Another one of those "reasoning problems" -_-

Question

@hartnn 
Another one of those "reasoning problems" -_-

anonymous · Answer

attachment

hartnn · Answer

$\Large \sqrt{25\times2} = \sqrt{25}\times \sqrt 2 = 5\sqrt 2$
do you get this ?

anonymous · Answer

Yes, the statement/calculation is false or incorrect. ^

hartnn · Answer

i mean
$4\sqrt {50} $
is actually
$4\times 5\sqrt 2 = 20\sqrt 2$
but that student did not simplify the radical term properly
he got $100\sqrt 2$ instead, which is incorrect

anonymous · Answer

^Ah, I understand ; good reasoning hartnn :)

hartnn · Answer

$\large 4\sqrt{25\times2} =4 \sqrt{25}\times \sqrt 2 = 4\times 5\sqrt 2=20\sqrt 2 \quad \huge \checkmark$

$\large 4\sqrt{25\times2} =4 \sqrt{25}\times \sqrt 2 = 4\times 25\sqrt 2=100\sqrt 2 \quad \huge \times$

anonymous · Answer

I have one more just like that which "reasoning" application -that I could use your help in.

hartnn · Answer

sure ask

anonymous · Answer

attachment

hartnn · Answer

do you find any mistake in that student's calculation ?

anonymous · Answer

wait, that's the wrong one, sorry.

hartnn · Answer

$\sqrt {12}$ is indeed $2\sqrt 3$
so no mistake

hartnn · Answer

ok

anonymous · Answer

no, the wrong file*

hartnn · Answer

its the same

anonymous · Answer

oh okay, I still had the other problem open.. that's why. The student is wrong because the  final simplified answer is $$-4\sqrt{3}$$

hartnn · Answer

he simplified $\sqrt{12}$
correctly, there is no error actually

anonymous · Answer

Exactly. Yay, thank you so much :)

hartnn · Answer

welcome :)