1.若x-2y+3=0.则6-2x+4y=?

若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 若5x+3y=3x+4y=x+2y+6,则x+y=___ 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 若x+y=4,则多项式1/2(x+y)+4(x-y)-3（x-y）-3/2(x+y)-x+y值是（） 1.若x-2y+3=0.则6-2x+4y=? （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 1.（X-Y）/13=Y/7问（x+y）/y=?.2.x/6=y/4=z/3(x.z.y不为0)则（X+3Y）/3Y-2Z=? 若2x=3y,则(x*x+y*y)/x*x=? 3(x+y)—4(x-y)=4,(x+y/2)+(x-y/6)=1.解方程组 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 若x^2-y^2=6 x+y=3 则x-y=多少 若x/y=4/3 则3x+2y/2x-5y= 若2x+2y=6x-3y,则x比y=