x^2-2x-1=0求:x^4+x^3-5x^2-7x+5的值

来源:学生作业帮助网 编辑:六六作业网 时间:2024/05/12 15:12:16
x^2-2x-1=0求:x^4+x^3-5x^2-7x+5的值x^2-2x-1=0求:x^4+x^3-5x^2-7x+5的值x^2-2x-1=0求:x^4+x^3-5x^2-7x+5的值X^2-2X-

x^2-2x-1=0求:x^4+x^3-5x^2-7x+5的值
x^2-2x-1=0
求:x^4+x^3-5x^2-7x+5的值

x^2-2x-1=0求:x^4+x^3-5x^2-7x+5的值
X^2-2X-1=0
X^4+X^3-5X^2-7X+5
=X^2(X^2-2X-1)+3X^3-4X^2-7X+5
=3X^3-4X^2-7X+5
=3X(X^2-2X-1)+2X^2-4X+5
=-2X^2-4X+5
=2(X^2-2X-1)+7
=7