x=√3 y=-1 求x²+2y²-xy
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y
已知|x+2|+(y+3)²=0,求6xy²-[3x²y-(2x²y-xy
若x=1/2,y=1 求x(x²+xy+y²)-y(x²+xy+y²)+3xy(
1/x+1/y=5,求2x-3xy+2y/x²+xy+y的值
已知x+y=3 xy=-5 求x设abc=1 求x²+3xy+2y²/x²y+2xy
若x+y=3,xy=1,且x>y,⑴求x²+y²的值.⑵求x-y的值
已知x=3 y=1\3,求3x²y-[2xy²-2﹙xy-3\2x²y﹚+xy]+3xy&
求3xy²-4x²y-2xy²+ 5x²y的值,其中x,y满足|x-1|+(y+
已知A=3x²y-xy²,B=xy-3x²y,且|x-1|+(y+3)²=0,求
已知|x²-2xy-8y²|+2√x²-4xy+4y²-1=0,求3x+6y的值
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
(1/x-y+1/x+y)÷2x/x²+2xy+y².其中x=-2.化解求值.求步骤!急!