Question

请教,初一整式除法知识点的题1,若x^2-2x-1=0 求x^4+x^3-5x^2-7x+5=2,ruo x^2-3x+

Answer 1

x^4+x^3-5x^2-7x+5

=x^4-2x^3+3x^3-5x^2-7x+5

=x^2(x^2-2x)+3x^3-6x^2+x^2-7x+5

=x^2(x^2-2x)+3x(x^2-2x)+x^2-2x-5x+5

将x^2-2x=1代入,可得 结果=7