大师作文网已知A=x³-2y³+3x²y+xy²-3xy+4,B=y³-x
来源：学生作业帮 编辑：大师作文网作业帮 分类：综合作业 时间：2024/11/10 18:36:16
已知A=x³-2y³+3x²y+xy²-3xy+4,B=y³-x³-4x²y-3xy-3xy²+3.
C=y³+x²y+2xy²+6xy-6,试说明对于xyz的任何值A+B+C是常数.
C=y³+x²y+2xy²+6xy-6,试说明对于xyz的任何值A+B+C是常数.
已知A=x³-2y³+3x²y+xy²-3xy+4,B=y³-x³-4x²y-3xy-3xy²+3.C=y³+x²y+2xy²+6xy-6,
试说明对于xyz的任何值A+B+C是常数.
A+B+C
= ( x³-2y³+3x²y+xy²-3xy+4) + (y³-x³-4x²y-3xy-3xy²+3) +( y³+x²y+2xy²+6xy-6)
= x³-2y³+3x²y+xy²-3xy+4 +y³-x³-4x²y-3xy-3xy²+3 + y³+x²y+2xy²+6xy-6
= 4 +3 -6
= 1
试说明对于xyz的任何值A+B+C是常数.
A+B+C
= ( x³-2y³+3x²y+xy²-3xy+4) + (y³-x³-4x²y-3xy-3xy²+3) +( y³+x²y+2xy²+6xy-6)
= x³-2y³+3x²y+xy²-3xy+4 +y³-x³-4x²y-3xy-3xy²+3 + y³+x²y+2xy²+6xy-6
= 4 +3 -6
= 1
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&#
已知A＝x³-2y³＋3x²y＋xy²-3xy＋4,B＝y³-x
已知:A=2x²-3x²y-2xy²,B=x²-2xy²+y³
x²（x+y)(y-x)-xy(x+y)(x-y) 已知a+b=4,ab=-2,求多项式3a²b+3
已知x+y=5,xy=3,x³+y³=(x+y)(x²-xy+y²),则1/x&
已知A=x³-2xy²+1,B=x³=xy²-3x²y.求多项式3A+
已知x+y=2,xy=1/2,求x³y+2x²y²+xy³
已知：A=x²+xy+y²,B=x²-xy+y²,x²+3xy+4y&
已知A=x²+xy+y².,B=x²-xy+y²,x²+3xy+4y&
已知2x²+xy=a,3y²+2xy=b,求4x²+8xy+9y²的值(用a,b
已知:6x²-7xy-3y²+14x+y+a=(2x-3y+b)(3x+y+1)求a,b的值