Question

分解因式X5+X4+X3+X2+X+1

Answer 1

原式=x^4(x+1)+x²(x+1)+(x+1)

=(x+1)(x^4+x²+1)

=(x+1)(x^4+2x²+1-x²)

=(x+1)[(x²+1)²-x²]

=(x+1)(x²+x+1)(x²-x+1)