Question

因式分解：x^4+ax^3-(2a^2+1)x^2-ax+2a^2

Answer 1

原式=(x^4-x²)+(ax³-ax)+(-2a²x²+2a²)

=x²(x²-1)+ax(x²-1)-2a²(x²-1)

=(x²-1)(x²+ax-2a²)

=(x+1)(x-1)(x+2a)(x-a)