已知,|x+y-5/2|+(x-2y+7/2)^2=0,求x^2009 ·y^2010的值...已知：|x+y-5/2|+(x-2y+7/2)^2=0,求x^2009 ·y^2010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|x-2y|+|5x-7y-2|则,x = y= 已知(x-y)^2+|5x-7y-2|=0,求x,y的值. 已知2x-y=-3,求代数式5(x-3y)-2(x-7y) 已知|5x-y-8|+(7y-x+2)=0则4x+6y 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 已知7x+5y/2y-x=3/2,且x≠0,求X/x-4y 已知2x-y/7x+5y=2/3且y≠0,求x/y的值 1、(-y^3)^5/y^3/ y^2+2(-y)^102、(x-y)^7/(y-x)^6+(x+y)^3/(x+y)^23、已知X^a=5,x^b=3,求X^(3a-2b)的值 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) 已知方程3(X-Y)^2-5X-2=2X-7Y-4.求X-Y的值 已知方程3(X-Y)^2-5X-2=2X-7Y-4.求X-Y的值 已知(3x+1)(3x-3)-3x+2)^2=-7,(y+7)(y-7)-y(y-7)=0,求8y^2-5y(-y+3x)+4y(-4y-5/2x)的值 已知:3(x-y)的平方-5x-2=2x-7y-4,求x-y的值 已知x+2y=2x+y+1=7x-5,求x和y的值 已知x+2y=2x+y+1=7x-5,求x和y的值 已知（x+y）2 =2,(x-y)3 =3,求(x+y)7(x-y)2(x+y)3(y-x)4 的值 已知方程组{(X+Y)-3(X-Y)=7,2(X+Y)+(X-Y）=-7}则(X+Y)(X-Y)=