解:原式=(x-1)(x-6)(x-2)(x+3)+56=[(x-1)(x-2)][(x-6)(x+3)]+56=(x^2-3x+2)(x^2-3x-18)+56把x^2-3x设做m则(m+2)(m-18)+56=m^2-16m-36+56=m^2-16m+20把x^-3x代入结果=x^4-25x^2+48x+20___________或许结果不对,但过程一定正确_________
