已知集合A={(x,y)|x²-y²-y=4},B={(x,y)|x²-xy-2y
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知集合A={(x,y)|x²+y²≤1.x.y∈R},B={(x,y)||x|+|y|≤2.x.y
已知集合A={(x,y)|(y-2)/(x-1)=a+2,x,y∈R},B={(x,y)|(a²-4)x+(a
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A除以x²+4xy+4y²分之x²-y²=x+2y分之x+2y,当x=2,y
已知集合A={y/y=x²}B={y/y=x}则A∩B=?
设集合A={x-y,x+y,xy},B={x²+y²,x²-y²,0},若A=B
设集合A={x-y,x+y,xy},B={x²+y²,x²-y²,0},且A=B
A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²+3x-y,若x=
已知2x-y=10,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y (4xy-2y²)/4
设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若x
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)