sqrt3x+16=x+2 What is the solution set?

Question

saifoo.khan · Answer

$$\sqrt{3x+16} = x+ 2$$If im not wrong..

saifoo.khan · Answer

x = 3

directrix · Answer

sqrt(3x+16)=x+2 OR sqrt(3x)+16=x+2 ? 

Cuddlepony -- which one?

anonymous · Answer

(2)^(3x + 16)^(1/2) = (x +2)^(2)
= 
3x + 16 = x^(2) + 4x + 4
=
0 = x^(2) + x - 12
=
(x + 4)(x-3)
so you are wrong

thus -4 and 3

anonymous · Answer

sorry I messed up notation but yeah I just squared both sides of the equation

anonymous · Answer

to elimanate the radical

anonymous · Answer

How should I know I wouldn't ask a question like this

anonymous · Answer

@Directrix

anonymous · Answer

or you are right and I mis interpreted the question meh

anonymous · Answer

only 3x+16 is the sqrt.

saifoo.khan · Answer

Then the answer's 3.

anonymous · Answer

x=-4 is an extraneous solution.  It doesn't work. (Try plugging it in.)

anonymous · Answer

Oh sorry I didnt complete the question by taking the domain

anonymous · Answer

You can't take the square root of [0, -infinity)

anonymous · Answer

did you have to use the quadratic equation?

anonymous · Answer

After you square both sides to clear the radical, you will almost always have a quadratic equation on these kinds of problems.

anonymous · Answer

ok, thanks so much!