m(x²-3x+1)-n(2x²-4x-2) =5x²-4x+p 求m、n、p的值

m(x²-3x+1)-n(2x²-4x-2) =5x²-4x+p 求m、n、p的值
m(x²-3x+1)-n(2x²-4x-2) =5x²-4x+p 求m、n、p的值

m(x²-3x+1)-n(2x²-4x-2) =5x²-4x+p 求m、n、p的值
mx²-3mx+m-2nx²+4nx+2n=5x²-4x+p
(m-2n)x²+(4n-3m)x+(m+2n)=5x²-4x+p
所以
m-2n=5
4n-3m=-4
m+2n=p
所以
m=-6
n=-11/2
p=-17

m(x²-3x+1)-n(2x²-4x-2) =5x²-4x+p
(m-2n)x²+(4n-3m)x+(2n+m)=5x²-4x+p
∴m-2n=5
4n-3m=-4
2n+m=p
∴m=-6
n=-11/2
p=-17

m(x²-3x+1)-n(2x²-4x-2)≡5x²-4x+p
mx²-3mx+m-2nx²+4nx+2n≡5x²-4x+p
(m-2n)x²+(4n-3m)x+m+2n≡5x²-4x+p
m-2n=5,4n-3m=-4,m+2n=p
解得，m=-6,n=-11/2,p=-17

mx²-3mx+m-2nx²+4nx+2n=5x²-4x+p
(m-2n)x²+(4n-3m)x+(m+2n)=5x²-4x+p
上面无论x取何值都得要成立
则当x=0时，也成立
＝＞m+2n=p
则
m-2n=5
4n-3m=-4
＝＞
m=-6
n=-11/2
p=-17