当(x+1)²+(y+1)²=0时,求3(2x²-xy-y²)-2(x²
当x=2,y=-1时,求代数式(x+y)(x-y)+(x-y)²-(x²-3xy)的值
当(x+1)²+(y+1)²=0时,求3(2x²-xy-y²)-2(x²
2x²-3xy=y²=0(x,y不得o)求x/y+y/x
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y
|x+2|+(y-1/4)²=0,求2(x²y+xy)-3(x²y-xy)-4x²
已知X²+Y²+X²Y²-4XY+1=0 求:(X-Y)^2008-(XY)^2
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
何老师给同学们出了一道题:当x=2013,y=2014时,求[2x(x平方y-xy²)+xy(2xy-x
已知x+y=3 xy=-5 求x设abc=1 求x²+3xy+2y²/x²y+2xy
已知(x+2)²+│y-1│=0,求7x²y-3+2xy²-6x²y-2xy