2X-3Y=-10 6X+5Y=12
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
已知x,y满足约束条件{2x+5y>=10,2x-3y>=-6,2x+y
解方程组:x+y/2+x-y/3=6 4(x+y)-5(x-y)=12
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
3x+2y=6 ,5x+6y=10那么x+y=?
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
2(2x+3y)(3x+2y)-(6x-y)(2x-5y) =12x^2+26xy+12y^2-
已知X,Y,满足(X+3Y)(X-3Y)=-10(Y^2-6/5)和2X(Y-1)+4(1/2X-1)=0
化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90)
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X