4條f.2數學(續多項式的因式分解)(7點!!)

1.(x^2+4x+4)－9y^2
=(x+2)^2－(3y)^2
=(x－3y+2)(x+3y+2)

2.25x^2－(9y^2－6y+1)
=(5x)^2-(3y－1)^2
=(5x－3y+1)(5x+3y－1)

3.(x^2+6xy+9y^2)－16z^2
=(x+3y)^2－(4x)^2
=(x+3y－4x)(x+3y+4x)
=3(y－x)(5x+3y)

4.4x^2－(4y^2－4yz+z^2)
=(2x)^2－(2y－z)^2
=(2x－2y+z)(2x+2y－z)