当x^2+x=3=0,求x^5+3x^4+2x^3+2x^2-10x+5
问题描述:
当x^2+x=3=0,求x^5+3x^4+2x^3+2x^2-10x+5
答
x^2+x+3=0x^2+x=-3x^5+3x^4+2x^3+2x^2-10x+5=x^5+x^4+2x^4+2x^3+2x^2-10x+5=x^3(x^2+x)+2x^4+2x^3+2x^2-10x+5=-3x^3+2x^4+2x^3+2x^2-10x+5=2x^4-x^3+2x^2-10x+5=2x^4+2x^3-3x^3+2x^2-10x+5=2x^2(x^2+x)-3x^3+2x^2-10...