\(x\left(x+1\right)\left(x+6\right)-x^3=5x\)
\(\Rightarrow\left(x^2+x\right)\left(x+6\right)-x^3=5x\)
\(\Rightarrow x^3+6x^2+x^2+6x-x^3=5x\)
\(\Rightarrow7x^2+6x=5x\)
\(\Rightarrow7x^2=-x\)
\(\Rightarrow7x=-1\)
\(\Rightarrow x=-\frac{1}{7}\)
Mặt khác: \(7x^2\ge0\)
\(-x\le0\left(x\ge0\right)\)
\(\Rightarrow x=0\)
Vậy \(x=-\frac{1}{7}\) hoặc \(0\)