若x=2y=1
设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
若变量x,y满足约束条件{x>=-1;y>=x;3x+2y
若全集I={(x,y)|x,y∈R},集合M={(x,y)|(y-3)/(x-2)},N{(x,y)|y=x=1},则(
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
若x=-1/4,能否确定代数式(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)的值?
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值
若x,y满足|2x-y-3|+|3x+2y+1|=0,则x= y=
方程组2x+y=1-m...x+2y=2中,若未知数x,y满足x+y
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
若7x+10y分之5x+y=1/2,则x/y=
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2