题目内容：

因式分解：4x^4-13x^2+9

优质解答

4x^4-13X^2+9
=(4x^4-4x^2)-(9x^2-9)
=4x^2(x^2-1)-9(x^2-1)
=(x^2-1)(4x^2-9)
=(x+1)(x-1)(2x+3)(2x-3)