1.y=3x-5 2.y=(x-2)/（x-1）3.y=根号x-1求取值范围

{(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 1.(2x-3y)(2x+3y)=2.（5x+3y）（3y-5x）3.（x-3y）（-x+3y）=4.（x+y-z）²= x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x^2-y分之y(x-y)-x(x+y)除以x+y分之x^2+y^2.其中x=2,y=-1.先化简再求值. （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 1.{5x=7y-1 5x=17-14y 2.{x=16-4y y=34-4x 3.{x+y=7 x:5=y:2 4.{x+2y=1 x-4y=-22 5.{3x=y+1/2 3x=y/4 1.{5x=7y-1 5x=17-14y 2.{x=16-4y y=34-4x 3.{x+y=7 x:5=y:2 4.{x+2y=1 x-4y=-22 5.{3x=y+1/2 3x=y/4 1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1