已知2^x=8^y+1,9^y=3^x-9,求1/3x+1/2y的值

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 已知2^x = 8^y+1,9^y = 3^x-9 ,1/3x+1/2y = 已知{2}^{x}={8}^{y=1},{9}^{-y}={3}^{x-8},求{x}^{y}的值 已知x+7y+9=0,则3（8y-x)+3(2x-y-1)的值是多少? 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 已知x,y满足（2X+3y+1)^2+/4x-9y-8/=0.求x,y的值. 已知x,y满足（2x+3y+1)的平方+|4x-9y-8|=0.求x,y的值 已知M={y|y=x²-4x+3,x∈R},N={y|y=-x²+2x+8,x∈R},求M∩N 答案是{y|-1≤y≤9} 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知2x-y/x+2y=3,求2(2x-y)/x+2y-9(x+2y)/2x-y+3的值. 9y=3x-(x-1),4(x+y)-(2x+4)=8y 已知x=2+根号3,y=2-根号3,计算代数式(x+y/x-y-x-y/x+y)乘以(1/x^2-1/y^2) 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y