Respuesta :

3x^2+4=40 
3x^2=36
x^2=12
x=+or-sqrt(12)

:)
MarkV
Hey there! 

Let's solve the equation step by step!
[tex]3 x^{2} + 4 = 40[/tex]

Subtract 4 from both sides.
[tex]3 x^{2} = 36[/tex]

Divide both sides by 3.
[tex] x^{2} = 12[/tex]

Solve the equation by taking the positive and negative root of 12.
[tex]x = \sqrt{12} = 2 \sqrt{3} = 3.46... \\or\\ x = - \sqrt{12} = -2 \sqrt{3} =3.46...[/tex]

The exact answer includes the roots, the other answer is the answer in two decimals. 
~Hope this helps you!