已知-6x^3+ax^2+8x+b=(x+1)(mx+1)(3x+n),求a,b,m,n的值

已知-6x^3+ax^2+8x+b=(x+1)(mx+1)(3x+n),求a,b,m,n的值
已知-6x^3+ax^2+8x+b=(x+1)(mx+1)(3x+n),求a,b,m,n的值

已知-6x^3+ax^2+8x+b=(x+1)(mx+1)(3x+n),求a,b,m,n的值
(x+1)(mx+1)(3x+n)
=[mx^2+(m+1)x+1](3x+n)
=3mx^3+[mn+3(m+1)]x^2+[n(m+1)+3]x+n=-6x^3+ax^2+8x+b
所以：3m=-6,m=-2
nm+n+3=8 n=-5
[mn+3(m+1)]=a,-2n-3=a,a=7
b=n=-5
a=7,b=-5,m=-2,n=-5