已知x2+x+3=0，求x5+3x4+2x3+2x2-10x的值．
网友回答
解：∵x2+x+3=0，
∴x2+x=-3，
x5+3x4+2x3+2x2-10x
=x3（x2+x）+2x4+2x3+2x2-10x
=-3x3+2x4+2x3+2x2-10x
=2x4-x3+2x2-10x
=2x2（x2+x）-3x3+2x2-10x
=-3x3-4x2-10x
=-3x（x2+x）-x2-10x
=9x-x2-10x
=-x2-x
=-（x2+x）
=3．
解析分析：要先提公因式，再根据x2+x+3=0得出x2+x=-3分别一步步代入，即可求出