2x^2=36

Question

2x^2=36

anonymous · Answer

solve by extracting the roots

luigi0210 · Answer

First what you have to do is get x by itself

anonymous · Answer

so divide by two and im left with x^2=3

luigi0210 · Answer

36/2 is 3?

anonymous · Answer

18

luigi0210 · Answer

There you go, now just take the square root of both sides

anonymous · Answer

x=+underoot (18) or
     - underoot (18)

luigi0210 · Answer

$$\sqrt{18}=\sqrt{9}*\sqrt{2}$$

anonymous · Answer

Wait... is it (2x)^2 or 2*(x^2) , the first case shall yield x= + or - 3, second ^^

anonymous · Answer

i got 4 for sqroot of 18 but my choices are x=3, x=-3   x=3      3sqroot2 or -3sqroot2

anonymous · Answer

What is the full question.. has the domain of x been mentioned like N (natural numbers)?

anonymous · Answer

solve the equation by extracting the square roots

luigi0210 · Answer

what is the sqrt9?

anonymous · Answer

3

luigi0210 · Answer

and 3*sqrt2?

anonymous · Answer

Oh , come on I know the roots! I'm asking about the domain? How can you say it's +3.. it can be -3 as well sqrt(9) shall give both positive and negative ones.

luigi0210 · Answer

Well the domain is all real numbers since it's a squared

luigi0210 · Answer

so it would be plus and minus $$3\sqrt{2}$$

anonymous · Answer

ok thanks

anonymous · Answer

Well if it is all real, x can be both positive and negative... if it's natural no, it can be only +3

anonymous · Answer

@Luigi0210  HOw is it 3*sqrt(2)?

luigi0210 · Answer

$$\sqrt{18}=\sqrt{9}*\sqrt{2}$$

anonymous · Answer

@kittakee : Write the question properly.  
Is it 
(2x)^2=36 
 or 2*(x^2) =36. They'll give different answers.

luigi0210 · Answer

Bro it's done.. I think