若A=8x²y-6xy²-3xy,B=7xy²-2xy+5x²y且C=3(A+B
设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²+3x-y.若x
设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若|
设A=2x²-3xy+y²-x+2y ,B=4x²-6xy+2y²+3x-y .
已知A=4x²-5xy+y²,B=x²+3xy-5y² 求:A-2B的值
已知a=2x²-3xy+y²,b=x²+2xy-3y²,化简:(1)a+b (2
问已知x²+y²=7,xy=-2,求5x²-3xy-4y²-11xy-7x&su
已知x²+y²=3xy且xy≠0,求x²y-²+x-²y²的
已知A=2x²y-xy²,B=x²y-3xy²,且3A-2B-C=0,求C的表达
3y/2x+2y+2xy/x²+xy 2x/x²-64y²-1/x-8y (1/a+1/b
已知X²-5XY+6Y²=0,求(X²+3XY)\2Y²的值
x/y=2,求分式x²-xy+3y²/x²+xy+6y²
若x/y=2,求7x²-3xy+2y²/2x²-3xy+7y²的值 答案是8/3