Question

这个问题我不会，求大神帮帮忙啊！谢谢

Answer 1

因为3x²-x=1，所以3x²=x+1
所以6x³+7x²-5x+2000
=x（6x²+7x-5）+2000
=x(2x-1）(3x+5)+2000
=（2x-1）（3x²+5x)+2000
=（2x-1）（1+x+5x)+2000
=(2x-1)(6x+1)+2000
=12x²-4x-1+2000
=4(3x²-x)+1999
=4*1+1999
=2003

Answer 2

我来

追答

6x^3+7x^2-5x+2000
=x[6x^2+7x-5]+2000
=x[2x-1][3x+5]+2000
=[2x-1][3x^2+5x]+2000
=[2x-1][1+x+5x]+2000
=[2x-1][6x+1]+2000
=12x^2-4x-1+2000
=4[3x^2-x]+1999
=4*1+1999
=2003

追问

这种解答我们没学，所以不能采纳，请谅解