解由25a(x-2y)^3+4a(2y-x)
=25a(x-2y)^3+4a(x-2y)
=a(x-2y)[25(x-2y)²-4]
=a(x-2y)[5²(x-2y)²-2²]
=a(x-2y)[(5x-10y)²-2²]
=a(x-2y)[(5x-10y+2)(5x-10y-2)]
=a(x-2y)(5x-10y+2)(5x-10y-2)
解由25a(x-2y)^3+4a(2y-x)
=25a(x-2y)^3+4a(x-2y)
=a(x-2y)[25(x-2y)²-4]
=a(x-2y)[5²(x-2y)²-2²]
=a(x-2y)[(5x-10y)²-2²]
=a(x-2y)[(5x-10y+2)(5x-10y-2)]
=a(x-2y)(5x-10y+2)(5x-10y-2)