\(\left(2x\right)^2\left(4x-2\right)-\left(x^3-8x^2\right)=15\\ =>4x^2\left(4x-2\right)-\left(x^3-8x^2\right)=15\\ =>16x^3-8x^2-x^3+8x^2=15\\ =>15x^3=15\\ =>x^3=1\\ =>x=1\)
\(X=1\)
\(X=-\) \(\dfrac{\sqrt{3i+1}}{2}\)
\(X=\) \(\dfrac{\sqrt{3i+1}}{2}\)