一道数学题因式分解：-2XY-X^2-Y^2 16(m-n)^2-9(m+n)^2
问题描述：
一道数学题因式分解：-2XY-X^2-Y^2 16(m-n)^2-9(m+n)^2
还有4x^2(x-y)+(y-x)
答
-2xy-x²-y²
=-(x²+2xy+y²)
=-(x+y)²
16(m-n)²-9(m+n)²
=[4(m-n)+3(m+n)]*[4(m-n)-3(m+n)]
=(7m-n)(m-7n)4x^2(x-y)+(y-x)4x²(x-y)+(y-x)＝4x²(x-y)－(x-y)＝(x-y)(4x²-1)=(x-y)(2x-1)(2x+1)