364. Solve the equation:

$$
x^{3}=6 x+40
$$

(elementary method).

## Wallis's Problem.
364. 

$$
x^{3}-6 x-40=0
$$

$$
\begin{gathered}
x^{3}-4 x^{2}+4 x^{2}-16 x+10 x-40=0 \\
x^{2}(x-4)+4 x(x-4)+10(x-4)=0 ; x_{1}=4 \\
x^{2}+4 x+10=0 ; x_{2}=-2 \pm i \sqrt{6}
\end{gathered}
$$

John Wallis (1616-1703), a prominent English mathematician; his main work "Arithmetica infinitorum" (1655). In another treatise "Treatise of algebra," he was the first to attempt a geometric representation of imaginary quantities. Wallis is one of the founders of the analysis of infinitesimals.