How would you solve How would you solve √(2x+5)=2√2 +1?

Question

danjs · Answer

like this like this 

$$[\sqrt{x}]^2=x$$

danjs · Answer

$$[\sqrt{2x+5}]^2=[2\sqrt{2}+1]^2$$

anonymous · Answer

Okay... so lemme try this

anonymous · Answer

Oh there should be an "x" after the second √2

danjs · Answer

you didn't type one, idk, look at the prob

anonymous · Answer

Yeah, I meant I mistyped it haha

anonymous · Answer

oh I see, I just didn't foil it when I did it last time... thanks!

anonymous · Answer

Appreciate it :).

danjs · Answer

$$[2x+5 = (2\sqrt{2}+1)(2\sqrt{2}+1)$$

danjs · Answer

welcome

anonymous · Answer

My textbook only lists one answer. Shouldn't there be two?

danjs · Answer

what is the prob, didnt you say you typed it in wrong

anonymous · Answer

Pretty much the second thing you typed

anonymous · Answer

except the 2x+5 is square root

danjs · Answer

$$\sqrt{2x+5}=2\sqrt{2}+1$$

that?

anonymous · Answer

The discriminant is positive so there should be two right? And yes, but after the root 2 on the right there should be an x (so root(2x))

danjs · Answer

$$2x+5=(2\sqrt{2}*x+1)(2\sqrt{2}*x+1)$$

anonymous · Answer

Yes, and I got the correct answer

anonymous · Answer

But only 1 listed  in the textbook whereas I got two

danjs · Answer

$$2x+5=8x^2+4\sqrt{2}*x+1$$

anonymous · Answer

Yep got the right answer using that

anonymous · Answer

There should be two though right?

danjs · Answer

only the positive answer

anonymous · Answer

both are positive... hmm whatever! I guess maybe the txtbook just ommitted one of them

anonymous · Answer

If you don't mind, how would I solve x^2-6ix-9?

anonymous · Answer

Would I just.. factor?

danjs · Answer

you cant solve that, there isn't an equation

anonymous · Answer

I think they want the imaginary answers

anonymous · Answer

ooohhh quadratic formula nvm

danjs · Answer

what do the directions say, it shouldn't be Solve

anonymous · Answer

Kk thanks!