若|x+2|+|y-2|=6-|x-3|-|y-1|,求x+y的最大值与最小值（要求写出过程）

若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 若2x=3y,则(x*x+y*y)/x*x=? x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 （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 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 2(x+y)-3(x-y)=1 6(x+y)+(x-y)=51 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 若5x+3y=3x+4y=x+2y+6,则x+y=___ 若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值 若x^2-y^2=6 x+y=3 则x-y=多少 若2x+2y=6x-3y,则x比y=