x=1 y=2 do x=x*y y=y+1 loop while y

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x=1 y=2 do x=x*y y=y+1 loop while y X=2 Y=4 Do x=x*y y=y+1 Loop While y 化简 x / y(x+y) - y / x(x+y) = （x-y)(x+y)-(x+y)^2+2y(y-x),其中x=1,y=3. 2y(x+二分之一y)-[(x+y)(x-y)+2y(y+x)],其中|x-1|=2 x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 y'/y=1/x y+y'-2y=2x 微分方程y - 2y' + y = x 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 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 x+x+y+y+y=21 ,x+x+y+y+y+y+y=27 ,x ,y=? x+x+y+y+y=21 ,x+x+y+y+y+y+y=27 ,x ,y=? x+2y=2x+y+1=7x-y 求：2x-y? 设x,y满足约束条件x+y>=1,x-y>=-1,2x-y 设x,y满足约束条件x+y>=1,x-y>=-1,2x-y 二元一次方程 ：2(x+y)-(x-y)=3 (x+y)-2(x-y)=1