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则z的最小值为? 3y/x*x-y*y+x/x*x-2xy+y*y+6y*y/x*x*x-x*x*y-xy*y+y*y*y等于多少? ·若x.y互为相反数,且（x+y+3)(x-y-2)=6,则x等于几 y=2/3x+6等于3y=2x+6吗? 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 3x-2y等于75 3y-2x等于5 x=?Y=? 2x+y等于6,x+3y+|3x-y|等于19,解此方程. 线性规划的简单题1.求z=x+3y的最大值2x+3y小于等于24x-y小于等于7y小于等于6x大于等于0y大于等于02.求z=7x+25y的最小值2x+5y大于等于15x+5y大于等于10x大于等于0y大于等于03.z=10x+15y的最大值x+2y小于等 x+y/2+x-y/6=5 2(x+y)-3(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 （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 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