9(a-b)²+12(a²-b²)+4(a+b)²a³-10a²+25ax²+2x+1-y²25（m+n-3）²-9（3m-2n）²

9(a-b)²+12(a²-b²)+4(a+b)²a³-10a²+25ax²+2x+1-y²25（m+n-3）²-9（3m-2n）²
9(a-b)²+12(a²-b²)+4(a+b)²
a³-10a²+25a
x²+2x+1-y²
25（m+n-3）²-9（3m-2n）²

9(a-b)²+12(a²-b²)+4(a+b)²a³-10a²+25ax²+2x+1-y²25（m+n-3）²-9（3m-2n）²
9(a-b)²+12(a²-b²)+4(a+b)²
=(3(a-b))+2*3*2(a+b)(a-b)+(2(a+b))²
=(3(a-b)+2(a+b))²
=(5a-b)²
a³-10a²+25a
=a(a²-2*5*a+5²)
=a(a-5)²
x²+2x+1-y²
=(x+1)²-y²
=(x+1+y)(x+1-y)
25（m+n-3）²-9（3m-2n）²
=(5(m+n-3))²-(3(3m-2n))²
=(5(m+n-3)+3(3m-2n))(5(m+n-3)-3(3m-2n))
=(14m-n-15)(-4m+11n-15)

1原式=【3（a-b）+2（a+b）】²
=（5a-b）²
2原式=a（a²-10a+25）
=a（a-5）²
3原式=（x+1）²-y²
=（x+1+y）（x+1-y）
4原式=【5（m+n-3）+3（3m-2n）】【5（m+n-3）-3（3m-2n）】
=（14m-n-15）（11n-4m-15）