15a^m+2b+12a^m+1b²-3a^mb^3 (x+y)²-4(x+y-1)
问题描述:
15a^m+2b+12a^m+1b²-3a^mb^3 (x+y)²-4(x+y-1)
a²(x-y)+b²(y-x)
-a^3-4a²+12a
答
15a^m+2b+12a^m+1b²-3a^mb^3=3a^mb(5a²+4ab-b²)=3a^mb(5a-b)(a+b)a²(x-y)+b²(y-x)=(x-y)(a-b)(a+b)-a^3-4a²+12a=-a(a-3)(a+4)(x+y)²-4(x+y-1)=(x+y-2)²a²(x-...