8x³y-9xy³=x³y 3x³+2x²=5x^5 3a²
8x³y-9xy³=x³y 3x³+2x²=5x^5 3a²
x²+3y-xy-3x= x³-x²-x+= x²-1-2xy+y= a
已知x+y=5,xy=3,x³+y³=(x+y)(x²-xy+y²),则1/x&
一.x-y=2,则x²-2xy+y²= 二.x-y=-1,xy=3,则x³y-2x
若A=x³-3x²y+2xy²+3y³,B=x³-2x²y+
若x²y=3,求2xy(x的5次方y的2次方-3x³y-4x)的值
先化简再求值,3xy²(xy+2y²-x²)+3x³y²,其中x=2,
因式分解x的5次方y-x³y+2x²y-xy
2x+y=0,求4x²+2xy(x+y)+y³
已知A=x³-2y³+3x²y+xy²-3xy+4,B=y³-x
已知A=2x²+3xy-y²,B=-1/2xy,C=1/8x³y³-1/4x
先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y