( -x-y )(x-y)=y²-x²若x²-y²=15,x-y=5,则x²+y²=( 17 )( x+1 )(x²-2x-1)不含1次项(括号内填一次二项式)计算:(x-y)²(y-x)²-(x-y)³(y-x)=0因式分解:x²+25xy+150y² =(x+10)(x+15) x的4次-5x²y²-36y的4次 =(x²+4y²)(x²-9y²)
-y-x9
6666