把下列各式分解因式1)x^2-9y^2减2x加6y=(x²-2x+1)-(9y²-6y+1)=(x-1)²-(3y-1)²=(x-1+3y-1)(x-1-3y+1)=(x+3y-2)(x-3y)
=(x^2-9y^2)-(2x-6y)=(x-3y)(x+3y)-2(x-3y)=(x-3y)(x+3y-2)
x^2-9y^2减2x加6y=(x+3y)(x-3y)-2(x-3y)=(x+3y-2)(x-3y)