x²-6xy+9y²-3x+9y+2
=(x-3y)²-3(x-3y)+2
=(x-3y-2)（x-3y-1)
x²+xy-6y²-6x+2y+8
=(x+3y)(x-2y)-6x+2y+8
=(x+3y-4)(x-2y-2)
m²-2mn+n²-5m+5n+6
=(m-n)²-5(m-n)+6
=(m-n-3）(m-n-2)
x²-6xy+9y²-3x+9y+2
=(x-3y)²-3(x-3y)+2
=(x-3y-2)（x-3y-1)
x²+xy-6y²-6x+2y+8
=(x+3y)(x-2y)-6x+2y+8
=(x+3y-4)(x-2y-2)
m²-2mn+n²-5m+5n+6
=(m-n)²-5(m-n)+6
=(m-n-3）(m-n-2)