数学因式分解题(3x^2-4x+5)(3x^2+4x-5)

问题描述:

数学因式分解题(3x^2-4x+5)(3x^2+4x-5)

把4x-5看成一个整体
=[3x^2-(4x-5)][3x^2+(4x-5)]
=9x^4-(4x-5)^2
=9x^4-(16x^2-40x+25)
=9x^4-16x^2+40x-25