Rút gọn biểu thức sau: −2x(3x−4)+(x+3)(2x−1).

\( - 2x\left( {3x - 4} \right) + \left( {x + 3} \right)\left( {2x - 1} \right).\)

\( = - 6{x^2} + 8x + 2{x^2} - x + 6x - 3\)

\( = \left( {2{x^2} - 6{x^2}} \right) + \left( {8x - x + 6x} \right) - 3\)

\( = - 4{x^2} + 13x - 3\).