Question

数学题,要过程和答案

解方程:(-3x)^2-(2x+1)(3x-2)-3(x+2)(x-2)=0
设m^2-m+1=0,求m^3-3m^2+3m-2011的值.
求解啊,不会做

Answer 1

1）:(-3x)^2-(2x+1)(3x-2)-3(x+2)(x-2)=0
9x^2-6x^2+x+2-3x^2+12=0
x=-14
设m^2-m+1=0,求m^3-3m^2+3m-2011的值.
m^3-3m^2+3m-2011
=m(m^2--3m+3)-2011
=m{(m^2--m+1)-2m+2}-2011
=m(-2m+2)-2011
=(-2m^2+2m)-2011
-2{(m^2-m+1)-1}-2011
=2-2011
=-2009

Answer 2

【1】
(-3x)^2-(2x+1)(3x-2)-3(x+2)(x-2)=0
解：9x²-（6x²-4x+3x-2）-3（x²-4）=0
9x²-6x²+x+2-3x²+12=0
x=-14
【2】
m^2-m+1=0,求m^3-3m^2+3m-2011的值
解：m²-m=-1【下面见到m²-m就换成-1】
m^3-3m^2+3m-2011
=m³-m²-2m²+3m-2011
=m（m²-m）-2m²+3m-2011
=-m-2m²+3m-2011
=-2m²+2m-2011
=-2（m²-m）-2011
=-2×（-1）-2011
=2-2011
=-2009

Answer 3

1- 原式展开为
9x^2-6x^2+x+2-3x^2+12=0
x=-14
2-
m^3-3m^2+3m-2011
=m(m^2-m+1)-2(m^2-m+1)-2009
=-2009

Answer 4

解方程:
(-3x)^2-(2x+1)(3x-2)-3(x+2)(x-2)=0
解：9x^2-6x^2+x+2-3x^2+12=0
x=-12
设m^2-m+1=0,
则：m=m^2+1
即：m^3-3m^2+3m-2011
=m(m^2-3m+3)-2010
=m(m^2+1-3m+2)-2010
=m(m-3m+2)-2010
=-2(m^2-m)-2010
=-2(m^2-m^2-1)-2010
=2-2010
=-2008

Answer 5

(-3x)^2-(6x^2-4x+3x-2)-(3x^2-6x+6x-12)=0
9x^2-6x^2+x+2-3x^2+12=0
x+14=0
x=-14

m^3-3m^2+3m-2011=m(m^2-3m+3)-2011

m^2-m+1=0 m^2-m=-1代入上式
=m(-1-2m+3)-2011
=-m-2m^2+3m-2011
=-(2(m^2-m)-2011
=-(2*(-1))-2011
=2-2011
=-2009

Answer 6

1. 原式得: 9x²-(6x²-x-2)-3(x²-4)=0
9x²-6x²+x+2-3x²+12=0
x=-14

2 因设为：m²-m+1=0
(m-1)²+m=0
得 m=-(m-1)²

m³-3m²+3m-2011
=m³-1³-2010-3m(m-1)
=(m-1)(m²+m+1)-3m(m-1)-2010
=(m-1)(m²+m+1-3m)-2010
=(m-1)(m-1)²-2010
代入 m=-(m-1)² 得 -m(m-1)-2010
即得 -m²+m-2010
因为 有设 m²-m+1=0 得-m²+m=1
所以 -m²+m-2010
=2009
m^3-3m^2+3m-2011的值为2009