.(x的平方-7x+6)(x的平方-x-6)+56
=(x-1)(x-6)(x-3)(x+2)+56
=(x-1)(x-3)(x-6)(x+2)+56
=(x2-4x+3)(x2-4x-12)+56
设x2-4x+3=A.得
A*(A-15)+56
=A2-15A+56
=(A-7)(A-8)
=(x2-4x-4)(x2-4x-5)
=(x2-4x-4)(X-5)(X+1)
.(x的平方-7x+6)(x的平方-x-6)+56
=(x-1)(x-6)(x-3)(x+2)+56
=(x-1)(x-3)(x-6)(x+2)+56
=(x2-4x+3)(x2-4x-12)+56
设x2-4x+3=A.得
A*(A-15)+56
=A2-15A+56
=(A-7)(A-8)
=(x2-4x-4)(x2-4x-5)
=(x2-4x-4)(X-5)(X+1)