In the radical equation √-4x-4 = x, you get x=-2. (-4x-4 is the complete radicand.)

Now, since radical equations only use principal roots, this comes out as no solution, correct? Although this confuses me, since technically √x = ± y

Also, one other thing:

16+36=c^2, so c=2√13, right? (It seemed really simple, so this answer seems a bit off.)