【Zih Ya Chen C】評論
x4+6x2+25=x4+10x2+25-4x2=(x2+5)2-2x2=(x2+2x+5)(x2-2x+5)(3x4+4x2+28x+5)除以(x2-2x+5)=3x2+6x+1.....整除b=-2,c=5b+c=3