Упростите выражение: (6x-x^2)^2-x^2(x-1)(x+1)+6x(3+2x^2).

\[\left( 6x - x^{2} \right)^{2} - x^{2}(x - 1)(x + 1) + 6x \cdot\]

\[\cdot \left( 3 + 2x^{2} \right) = 36x^{2} - 12x^{3} + x^{4} - x^{2} \cdot\]

\[\cdot \left( x^{2} - 1 \right) + 18x + 12x^{3} = x^{4} + 36x^{2} +\]

\[+ \ 18x - x^{4} + x^{2} = 37x^{2} + 18x\]