已知x+y=0,x+3y=1,求3x^2+12xy+13y^2 的值

已知:3x-5y=0,求x/y,x-y/y,x-y/x 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知|2x-3y|+|3x-y-1|=0,求x,y的值. 已知X,Y满足|X-Y-1|+（X+Y-3)^2=0求X,Y的值 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知|3x-y|+|x+y|=0,求x-y除以x*y的值. 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=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x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y) 已知2x-y=0,求分式【1+（3*y*y*y/x*x*x-y*y*y）】/【1+（2y/x-y）】的值注：x*x*x-y*y*y=（x-y）*（x*x+xy+y*y） 已知:x-2y+3=0 求x^2-(4y+1)x+4y^2+2y 已知x、y满足2/1|x-y|+|1-y|=0,求7x-3y的值 已知：x,y满足|2x-y|+|y-1/2|=0,求7x-3y的值. 已知x+y=0,求x^3+x^2*y+xy^2+y^3 已知X-Y=3,求X-Y的2次幂减3X+3Y+1