4x+2y=20,

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 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (x-4y)(2x+y)= 2元一次方程组 2/x+y+3/x-y=6 4(x+y)-3(x-y)=-20 已知X,Y满足x+y=4,x^2-y^2=20,求x,y的值 解方程组;x+y/2=x-y/3=6 4(x+y)-3(x-y)=-20 x^2+y^2-2x+4y-20=0则y/x的最大值,x+y的最大值 已知x+y=4,x^2-y^2=20,求x-y! 已知x+y=4,x^2+y^2=20,求x-y的值 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 4x方y/(x-2y)(x+2y)怎么算[x方/x-2y]-4x方y/(x-2y)(x+2y)=? 方程组：x(y+1)+2(y+1)=y(y-1)x-5(y-1) x（4+y）-y（8-x）=-20x(y+1)+2(y+1)=y(y-1)x-5(y-1) x（4+y）-y（8-x）=-20（这是一个方程组.） 一道方程,求:X(4+Y)-Y(8-X)=-20错了,是X(Y+1)+2(Y+1)=(Y-1)X-59(Y-1)X(4+Y)-Y(8-X)=-20这是一个方程组 (x+y)^2(x-y)^2(x^4+x^2y^2+y^4)=? y'=（y/x）^2+y/x+4微分方程 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1