Respuesta :

So,

We could use the pythagorean theorem as follows:

[tex](3x)^2+x^2=(\sqrt[]{40})^2[/tex]

And then solve for x:

[tex]\begin{gathered} 10x^2=40 \\ x^2=\frac{40}{10} \\ x^2=4 \\ x=2 \end{gathered}[/tex]

Therefore, x=2.