y=2/3x+6等于3y=2x+6吗?
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
简单的线性规划题,设Z=2y-x,满足X,y:y小于等于x,x+y大于等于2,y大于等于3x-6
4x=-6y两边同时-(2X-3y)合并等于4x-(2x-3y)=-6y-(2x-3y)等于2x+3y=-3y-2x完后
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
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
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
2x+y等于6,x+3y+|3x-y|等于19,解此方程.
x/4+2等于x,x=多少.y/5等于y-3,Y=多少
若/x+y-2/+(2x-3y+6)的平方等于0则x=( )y=( )