+9 Find all values of $x$ such that $\sqrt{4x^2} - \sqrt{x^2} = 6$.
Ive seen the other answers on this site, but none of them make any sense... i just need the answers. Idc about the explaination.
Thanks!
You're going to get the explanation anyway.
You're not the only one who reads these threads.
Take into account that square roots are both positive and negative.
sqrt(4x2) = +2x and –2x (i.e., plus and minus roots)
sqrt (x2) = +x and –x
2x – x = 6 gives you x = 6
–2x – x = 6 gives you x = –2
2x – (–x) = 6 gives you x = 2
–2x – (–x) = 6 gives you x = –6
