已知﹛x=1,y=-1;﹛x=-3,y=-7是方程ax+by=5的解.求a和b

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)]÷y的值 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:3x-5y=0,求x/y,x-y/y,x-y/x 已知x,y满足{x>=1,x+y 已知x,y满足{x>=1,x+y 已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 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x(x-1)-(x²+y)=3 求x(x-y)+(y-x)的值 已知x×x×y×y+x×x+y×y+1=4xy,求x,y的值快 已知x,y是整数,且x(x-y)+2012y(x-y)=1,求x,y的值. 已知x:y=3:1,且x+y=12,求x-y的值. 已知3x+4y-6x-1-y=0,那么x-y=_______. 已知x/3=y/4,求(1+x/y)/(1-x/y)的值! 已知X-Y=3,求X-Y的2次幂减3X+3Y+1 已知|2x-3y|+|3x-y-1|=0,求x,y的值. 已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? 已知3x-4y/2x+y=1/2 求x/y的值