如果(2x+2y+1)(2x+2y-1)=31,则(X+Y)^2=

1、x(x-y)(x+y)-x(x+y)^2 设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于 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 如果x/y=2/3且x不等于2,则x-y+1/x+y-5的值 (1)(x^2/x)-y-x-y (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 已知4x=9y求(1)x+y/y (2)y-x/2x {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 y=(x^2+x)/(x+1) 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( 2(x+y) 3x+3y=24 x+y/2x x y/2y= 1 [(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y