x³+3x²+4x+4因式分解我用试根法做出来是(x+2)(x²+x+2)不知道对不对

问题描述:

x³+3x²+4x+4因式分解
我用试根法做出来是(x+2)(x²+x+2)不知道对不对

x*(x*x+3x+2)+2(x+2)=x*(x+1)*(x+2)+X(x+2)=(x+2)(X*X+2x)

x³+3x²+4x+4=x³+x²+2x+2x²+2x+4=x²(x+1)+2x(x+1)+2(x+2)=x(x+1)(x+2)+2(x+2)=[x(x+1)+2](x+2)=(x²+x+2)(x+2)

x³+3x²+4x+4
=x²(x+2)+x²+4x+4
=x²(x+2)+x(x+2)+2x+4
=x²(x+2)+x(x+2)+2(x+2)
=(x+2)(x²+x+2)

x³+3x²+4x+4
=x³+2x²+x²+4x+4
=(x³+2x²)+(x²+4x+4)
=X²(X+2)+(X+2)²
=(X+2)(X²+X+2)